LEICA CM1850 User Guide

Instruction Manual

Leica CM1850 V2.2 English – 12/2003
Always keep this manual near the instrument!

Read carefully prior to operating the instrument!

Leica CM1850

Cryostat

INFORMATION

The information, numerical data, notes and value
judgments contained in this manual represent the
current state of scientific knowledge and state­of-the-art technology as we understand it follow­ing thorough investigation in this field. We are
under no obligation to update the present manual
periodically and on an ongoing basis according
to the latest technical developments, nor to pro­vide our customers with additional copies, up­dates etc. of this manual.
For erroneous statements, drawings, techni­cal illustrations etc. contained in this manual
we exclude liability as far as permissible ac­cording to the national legal system applicable
in each individual case. In particular, no liabil­ity whatsoever is accepted for any financial loss
or consequential damage caused by or related
to compliance with statements or other infor­mation in this manual.
Statements, drawings, illustrations and other
information as regards contents or technical
details of the present manual are not to be con­sidered as warranted characteristics of our
products.

These are determined only by the contract pro­visions agreed between ourselves and our
customers. Leica reserves the right to change
technical specifications as well as manufac­turing processes without prior notice. Only in
this way is it possible to continuously improve
the technology and manufacturing techniques
used in our products.

This document is protected under copyright laws.
Any copyrights of this document are retained by
Leica Microsystems Nussloch GmbH.

Any reproduction of text and illustrations (or of
any parts thereof) by means of print, photocopy,
microfiche, web cam or other methods – includ­ing any electronic systems and media – requires
express prior permission in writing by Leica
Microsystems Nussloch GmbH.

For the instrument serial number and year of
manufacture, please refer to the name plate at
the back of the instrument.

© Leica Microsystems Nussloch GmbH

Leica Microsystems Nussloch GmbH
Heidelberger Str. 17 - 19
D-69226 Nussloch
Germany

Phone: [phone]
Fax: [phone]
eMail: [e-mail]
Internet: http://www.histo-solutions.com

Leica CM1850 – Cryostat

3

Table of contents

1. Important Information ................................................................................................................ 6

1.1 Symbols used in this manual and their meaning ...................................................................................... 6

1.2 Qualification of personnel ............................................................................................................................. 6

1.3 Designated use ................................................................................................................................................ 6

1.4 Instrument type: ............................................................................................................................................6

2. Safety ............................................................................................................................................ 7

2.1 Safety features..............................................................................................................................................7

2.1.1 Locking the handwheel............................................................................................................................... 7

2.1.2 Knife guard .....................................................................................................................................................8

2.2 General information on instrument design and safe handling ..............................................................8

2.3 Operating conditions ...................................................................................................................................9

2.5 Cleaning and disinfection.........................................................................................................................10

2.6 Removal of the microtome ........................................................................................................................10

2.7 Maintenance ............................................................................................................................................... 11

3. Technical data .......................................................................................................................... 12

4. Unpacking and installation ....................................................................................................14

4.1 Site requirements........................................................................................................................................14

4.2 Transport to the desired location ...........................................................................................................14

4.3 Standard delivery........................................................................................................................................ 15

4.4 Handwheel assembly .................................................................................................................................16

5. Setup ........................................................................................................................................... 17

5.1 Connection to mains power ..................................................................................................................... 17

5.2 Prior to operation ........................................................................................................................................ 17

5.3 Leica CM1850 - Overview ..........................................................................................................................18

5.4 Mains switch and automatic mains fuse ..............................................................................................20

5.5 Turning the instrument on ........................................................................................................................ 20

6. Control panel operation........................................................................................................... 21

6.1 Control panel 1 ............................................................................................................................................ 21

6.2 Programming the desired values.............................................................................................................21

6.2.1 Setting the time ...........................................................................................................................................21

6.2.2 Setting the automatic defrost time (cryochamber) ............................................................................ 22

6.2.3 Selecting the cryochamber temperature ..............................................................................................22

6.2.4 Activation of the Peltier element (option).............................................................................................23

6.2.5 Manual defrosting of the quick freeze shelf ........................................................................................23

6.2.6 Manual defrosting of the cryochamber ................................................................................................ 24

6.3 Display lock ..................................................................................................................................................24

6.4 Control panel 2 - Electric coarse feed ................................................................................................... 25

4

Instruction Manual V 2.2 – 12/2003

Table of contents

7. Daily use of the instrument..................................................................................................... 26

7.1 Specimen freezing ......................................................................................................................................26

7.1.1 Quick freeze shelf....................................................................................................................................... 26

7.1.2 Stationary heat extractor (accessory)* ................................................................................................ 26

7.2 Specimen discs ........................................................................................................................................... 27

7.2.1 Inserting the specimen discs in the specimen head .........................................................................27

7.2.2 Specimen orientation ................................................................................................................................27

7.3 Sectioning ....................................................................................................................................................28

7.3.1 Trimming the specimen .............................................................................................................................28

7.3.2 Section thickness setting ......................................................................................................................... 28

7.4 Temperaturew selection chart (in minus °C) ....................................................................................... 29

7.5 Defrosting ..................................................................................................................................................... 30

7.5.1 Automatic defrosting of the cryochamber............................................................................................30

7.5.2 Manual defrosting of the cryochamber ................................................................................................ 30

7.5.3 Manual defrosting of the quick freeze shelf ........................................................................................31

7.6 Terminating work ........................................................................................................................................ 31

7.6.1 Terminating daily work ..............................................................................................................................31

7.6.2 Shutdown for a longer period .................................................................................................................. 32

8. Troubleshooting ........................................................................................................................ 33

8.1 Error messages in the display ..................................................................................................................33

8.2 Temperature control button .....................................................................................................................33

8.3 Possible causes and remedies................................................................................................................34

9. Cleaning, disinfection, maintenance.................................................................................... 39

9.1 Cleaning ........................................................................................................................................................ 39

9.2 Spray disinfection with Leica Cryofect..................................................................................................40

9.3 Maintenance ............................................................................................................................................... 41

9.3.1 General maintenance ................................................................................................................................41

9.3.2 Removal of the microtome ........................................................................................................................ 42

9.3.3 Removal of the microtome cover.............................................................................................................44

9.3.4 Reinstallation of the microtome .............................................................................................................. 44

9.3.5 Replacement of the fuses.........................................................................................................................46

9.3.6 Replacement of the lamp ..........................................................................................................................46

10. Ordering information, optional accessories........................................................................ 48

10.1 Ordering information ..................................................................................................................................48

10.2 Optional accessories................................................................................................................................. 49

10.2.1 Mobile heat extractor................................................................................................................................49

10.2.2 Thermal block ..............................................................................................................................................49

11. Warranty and service ..............................................................................................................50

Leica CM1850 – Cryostat

5

1. Important Information

1.1 Symbols used in this manual and
their meaning

Warnings
appear in a grey box and are marked
by a warning triangle .

Notes
i.e. important user information ap­pears in a grey box and is marked by
an information symbol.

Figures in brackets refer to item num-

(5)

(Fig.5)

bers in drawings or to the drawings
themselves.

1.2 Qualification of personnel

The Leica CM1850 may only be operated by
trained laboratory personnel.
All laboratory personnel designated to oper­ate the instrument must carefully read the
present instruction manual prior to starting
work with the instrument.

1.3 Designated use

The Leica CM1850 is a powerful cryostat for
routine as well as research applications in bi­ology, medicine and industry.
The instrument has been designed for rapid
freezing and sectioning of tissue samples.
The instrument has not been designed for un­attended storage of tissue material.
The instrument may only be operated within
the scope of its designated use as described
above and as per the instructions given in this
manual.
Any other use of the instrument is considered
improper.

1.4 Instrument type:

All information given in this instruction manual
applies only to the instrument type indicated
on the title page.

A name plate, indicating the instrument serial
number, is attached to the back of the instru­ment.

Fig. 1

6

Instruction Manual V 2.2 – 12/2003

2.1 Safety features

2. Safety

This instruction manual includes important instructions and information
related to the operating safety and maintenance of the instrument.
The instruction manual is an important part of the product. It must be
read carefully before using the instrument for the first time and must
always be kept with the instrument.
If additional requirements, which exceed the scope of this manual, are
imposed by regulations and/or laws on accident prevention and envi­ronmental protection in the country of operation, appropriate instruc­tions for compliance with such requirements must be added to this
manual.
Read this instruction manual carefully before attempting to use or oper­ate the instrument.

The instrument and its accessory equipment incorporate the following
safety features: safety handwheel and knife guards on the knife hold­ers.
The consistent use of these safety features and strict observation of the
warnings and cautions in this manual, will safeguard the operator from
accidents and/or personal injury to a great extent.

2.1.1 Locking the handwheel

2

1

For locking the handwheel rotate the handle until it is in the upper position.
Push the locking pin (1) into the recess at the handwheel. The locking posi-
tion is marked by a black dot (2). If necessary, move the handwheel slightly

Fig. 2

Fig. 3

Leica CM1850 – Cryostat

forth and back until the locking mechanism engages.

To unlock, push the locking pin (1) to the left from the recess at the handwheel.

Prior to manipulating the knife and specimen, or changing the
specimen or knife, and during breaks, always lock the handwheel!

7

2. Safety

2.1.2 Knife guard

For every manipulation in the cryochamber, or upon changing a
specimen when the knife or disposable blade is clamped, or dur­ing breaks, cover the cutting edge with the knife guard.

The knife holders CN and CS are equipped with knife guards; on the knife
holder CE the glass plate of the anti-roll guide constitutes the knife guard
(please refer to the separate instruction manual for your knife holder).
Prior to manipulating the knife and specimen, or changing the specimen
or knife, and during breaks, always lock the handwheel!

2.2 General information on instrument design and safe handling

This instrument has been built and tested in accordance with the follow­ing safety regulations on electrical measuring, control, regulating and
laboratory devices:

• DIN EN 292,

• DIN EN 61010-1,

• EN 50082-1,

• EN 55011,

• IEC 1000-4
as well as according to the international quality standard,

• DIN ISO 9001.

In order to maintain this condition and to ensure safe operation, the opera­tor must observe the instructions and warnings contained in this in­struction manual.

8

Instruction Manual V 2.2 – 12/2003

2.3 Operating conditions Transport and installation

• After transporting do not turn the instrument on for a minimum of 4

• Do not operate in rooms with explosion hazard!

• To ensure an adequate cooling capacity, the instrument must be set

Connection to mains

• Before connecting to the mains power, please check if the local volt-

• During the compressor start-up the nominal voltage must not drop

• After transporting, wait at least 4 hours before turning the instrument

Defrosting

2. Safety

hours!

up with at least 10 cm distance from walls and furniture!

age complies with the power rating specified on the name plate of
the instrument!

below the values specified in the ‘Technical data‘!
The compressor requires a start-up current between 45 and 50 A.
Therefore, the electric circuit at the place of installation must be in­spected by an electrical engineer to ensure that it meets the require­ments for a smooth operation of the instrument.
A constant adequate power supply to the instrument must be en­sured at all times.
Failure to comply with the above will cause severe damage to the
instrument.

on.
This waiting period is necessary to allow the compressor oil, which
may have been displaced during transport, to return to its original
position.
Failure to comply with this can cause severe damage to the instru­ment.

• The quick freeze shelf may become hot during defrosting!
Therefore, do not touch it!

2.4 Operating the instrument

• Take care when handling microtome knives and disposable blades.
The cutting edge is extremely sharp and can cause severe injury!

Leica CM1850 – Cryostat

9

2. Safety

• Never leave knives and knife holders with a knife/blade mounted
lying around!

• Do not place a knife on a table with the cutting edge facing upward!

• Never try to catch a falling knife!

• Always clamp the specimen before the knife!

• Prior to manipulating the knife and specimen, or changing the speci­men or knife, and during breaks, always lock the handwheel and
cover the cutting edge with the knife guard!

• Avoid contact with cold parts of the instrument as this can cause
frostbite!

• To make sure that the condensation water stemming from the de­frost cycles drains into the waste container and to avoid the risk of
possible contaminations, ensure that the tap of the waste container
(2, Fig. 31.1) is open when operating the instrument. Only shut the tap
when draining the waste container!

2.5 Cleaning and disinfection

• It is not necessary to remove the microtome for routinely disinfecting
the cryochamber.
The instrument is appropriate for spray disinfection with Leica
Cryofect!

• Do not use organic solvents or any other aggressive substances for
cleaning and disinfection!
Only use the cleaning agents and disinfectants specified in this in­struction manual such as Leica Cryofect (alcohol or common disin­fectants based on alcohol)!

2.6 Removal of the microtome

• Prior to removing the microtome, turn the instrument off with the mains
switch and pull the mains plug.

• Prior to removing the microtome, bring the specimen head to the lower
position with the handwheel.
Otherwise the specimen head would rapidly fall down and might in­jure the operator‘s hands, when taking out the microtome.

• Wear appropriate protective gloves to take the cold microtome out of
the cryochamber.

10

Instruction Manual V 2.2 – 12/2003

.2.7 Maintenance

Replacement of the fuses

2. Safety

Extended skin contact with cold parts of the instrument may cause
frost bite!

• The microtome must be entirely dry before reinstallation. Humidity

inside will condense and freeze in the cold cryostat and thus cause
malfunctions or damage.

• Do not use external heaters for drying the cryochamber. This can

cause damage to the cooling system!

• All components removed from the cryostat must be carefully dried

before they are replaced in the cryochamber

• Turn the instrument off with the automatic mains fuse and pull the

mains plug, before replacing the fuses.

• Only use fuses of the same specification! For the required values,

please refer to Chapter 3 ‘Technical data‘.
The use of fuses other than specified by the manufacturer may cause

severe damage to the instrument!

Replacement of the lamp

Leica CM1850 – Cryostat

• Turn the instrument off with the automatic mains fuse and pull the

mains plug, before replacing the lamp.

• If the lamp is broken, it must be replaced by the technical service, as

the replacement involves a high risk of injury.

11

3. Technical data

Operating temperature range (ambient temperature): 18 °C to 40 °C.
All specifications related to temperature are valid only up to an ambient temperature of 22 °C
and an air humidity lower than 60%!

Type CM1850 CM1850 CM1850-08 CM1850-01

Mark of conformity CUL - - VDE
Nominal voltage (±10%) 120 V AC 220 V AC 230 V AC 240 V AC
Nominal frequency 60 Hz 60 Hz 50 Hz 50 Hz
Power draw 1600 VA 1600 VA 1600 VA 1600 VA
Max. start-up current for 5 sec 45A eff. 45A eff. 45A eff. 45A eff.
Protective class I I I I
Automatic mains fuse T12A T1 T12A T1 T10A T1 T10A T1
Pollution degree 2 2 2 2

Overvoltage installation category

Heat emission (max.) 1600 J/s 1600 J/s 1600 J/s 1600 J/s

Refrigeration system 50 Hz 60 Hz

Cryochamber
Temperature setting range 0°C to -35°C (+ 2 K / - 0 K) 0°C to -35°C (+ 2 K / - 0 K)
Defrosting automatic hot gas defrosting, automatic hot gas defrosting,

Refrigeration capacity 690 W 690 W
Safety factor 3 3
Refrigerant 300 g ±5g refrigerant R 404A * 300 g ±5g refrigerant R 404A *
Compressor oil 0.6 l EMKARATE RL-22S, ICI * 0.6 l EMKARATE RL-22S, ICI *

II II II II

temperature controlled temperature controlled
1 automatic defrost cycle/24 hours, 1 automatic defrost cycle/24 hours,
temperature controlled temperature controlled
manual defrost cycle manual defrost cycle

Quick freeze shelf
Max. temperature -40°C (+ 0 K / - 2 K) - 40°C (+ 0 K / - 2 K)
Number of quick freeze stations 10 10
Defrosting manual hot gas defrosting manual hot gas defrosting

time controlled time controlled
Peltier element (option)
Max. temperature -60°C (+5 K) -60°C (+5 K)
Number of freezing stations 2 2*
Defrosting together with quick freeze shelf together with quick freeze shelf

12

Instruction Manual V 2.2 – 12/2003

3. Technical data

* Refrigerant and compressor oil must only be replaced by qualified, authorized service per­sonnel!

Microtome

Rotary microtome
Section thickness setting 1 - 60 µm
Specimen feed 25 mm
Vertical stroke 59 mm
Maximum specimen size 55 x 55 mm
Specimen orientation 8° (x-, y-, z-Achse)
Electric coarse feed

slow 0.2 mm/s
rapid 0.7 mm/s

Cryocabinet

Dimensions

Width (w/o handwheel) 600 mm
Width (with handwheel) 730 mm
Depth 730 mm
Height 1140 mm

Weight (incl. microtome,
without specimen cooling) approx.135 kg

Fluorescent lamp

50 Hz version: Osram Dulux S 11 W/21

Color: LUMILUX light white

60 Hz version: Osram Dulux S 13 W/21

Color: LUMILUX light white

➀ according to IEC-1010, UL 3101
➁ according to CECOMAF

Liquid temperature 45°C
Evaporation temperature -25°C

Please refer to section 5.2 ‘Site require­ments‘!

All CM 1850 types require the following fuses:

F1: T0,25 A Fa. Schurter, Typ FST; 6,3x32 mm or T0,25 A Fa. Littlefuse, Typ 313; 6,3x32 mm
F2: T0,6 A Fa. Schurter, Typ FST; 6,3x32 mm or T0,6 A Fa. Littlefuse, Typ 313; 6,3x32 mm
F3: T1,6 A Fa. Schurter, Typ FST; 6,3x32 mm or T1,6 A Fa. Littlefuse, Typ 313; 6,3x32 mm
F4: T6,25 A Fa. Schurter, Typ FST; 6,3x32 mm or T6,25 A Fa. Littlefuse, Typ 313; 6,3x32 mm
F5: T4 A Fa. Schurter, Typ FST; 6,3x32 mm or T4 Fa. Littlefuse, Typ 313; 6,3x32 mm

Leica CM1850 – Cryostat

13

4. Unpacking and installation

4.1 Site requirements

Do not operate in rooms with explosion hazard!To ensure an ad­equate cooling capacity, the instrument must be set up with at
least 10 cm distance from walls and furniture.

• The place of installation must meet the following requirements:
– no direct sunlight,

– mains power socket at a distance no greater than approxi-

mately 1.5 m,
– no drafts (air condition outlets, etc.) directly over the instrument,
– even floor,
– mainly vibration-free floor,
– obstruction-free access to the handwheel,
– room temperature max. 35°C,
– Air humidity must not exceed 60% High room temperatures and ex-

cessive air humidity affect the cooling capacity of the cryostat.

High room temperatures and excessive air humidity affect the
cooling capacity of the cryostat.

4.2 Transport to the desired location

• Move the instrument to the installation site on its wheels (14). Please
note the areas which are reinforced for tarnsporting and grip the

Tilt

cabinet only at these locations (Fig. 4).

• The adjustable feet (15) can support the weight of the instrument
when tipping at a slight angle (max. 30 °).

• At the installation site unscrew the screws in the adjustable feet (15)
using a fork wrench.
This is necessary to ensure stability.

• Align the adjustable feet to level the instrument.

The instrument must be transported in an upright position only.
When the instrument is tilted, the compressor oil is displaced.
Do not grip the cabinet at the lid. Grip the cabinet only at the

marked locations ( ).
The alignment of the adjustable feet is necessary to ensure an
unobstructed drain of the quick freeze shelf defrosting water.

Fig. 4

16

Lengthwise
movement

Sideways
movement

15

14

14

Instruction Manual V 2.2 – 12/2003

4. Unpacking and installation

4.3 Standard delivery

It gives following variations: - CM1850 with Retraction ............................................. 0471 31150

- CM1850 without Retraction (only US) ..................... 0471 31148

1 Handwheel, assy. ......................................................................................... 0416 18478

1 Heat extractor, stationary ......................................................................................... 0471 30792

1 Low temperature stabilizer for heat extractor, (Parking station) ................................... 0471 30793

1 Optional clamping lever for object head ............................................................................. 0112 28806

3 Specimen discs, 25mm diameter ......................................................................................... 0416 19275

1 Section waste tray ......................................................................................... 0471 30787

1 Storage shelf, right ......................................................................................... 0471 30789

1 Storage shelf, left ......................................................................................... 0471 30790

1 Brush, fine ......................................................................................... 0183 28642

1 Leica brush ......................................................................................... 0183 30751

1 Brush shelf ........................................................................................ (0398 13088

1 Tool set:

- 1 Allen key, size 2.5 ......................................................................................... 0222 04137

- 1 Allen key, size 3 ........................................................................................ 0222 04138

- 1 Allen key with spherical head, size 4 ............................................................................. 0222 32131

- 1 Allen key, size 6 ......................................................................................... 0222 04141

- 1 Single-head wrench, size 16 ......................................................................................... 0330 18595

1 Bottle of cryostat oil, type 407, 50 ml ..................................................................................... 0336 06098

1 Bottle of OCT-Compound, mounting medium for cryosectioning, 125 ml ..................... 0201 08926

1 Instruction manual Leica CM1850 - G/E/F/S ........................................................................ 0708 37106

Leica CM1850 – Cryostat

Compare the delivered components with the parts list and your order.
Should you find any discrepancies, please contact your Leica sales of­fice without delay.

A choice of different knife holders is available for the CM 1850.
The knife holder is accompanied by its own separate instruction
manual.
Please contact your Leica sales office if the instruction manual
is missing.

15

4. Unpacking and installation

4.4 Handwheel assembly

1

2

• Insert the pin (1) of the handwheel shaft in
to the hole (2) of the handwheel.

Fig. 5

3

4

5

• Mount the spring washer (3) on the screw (4)
as shown in Fig. 16.

• Tighten the screw (4) with an Allen key (5 mm).

• Attach the cover disc (5) (self-adhesive).

To dismount, proceed in reverse order.

The handwheel including the fixing components are packed in the
cardboard box for the accessories.The handwheel can be dis­mounted for transporting (e.g. narrow doors).

16

Instruction Manual V 2.2 – 12/2003

5.1 Connection to mains power

• The electric circuit at the place of installation must be protected sepa­rately.

• Do not connect any other consumers to this electric circuit.

5.2 Prior to operation

• Before connecting the instrument to the mains power, please check if
the local mains voltage complies with the power rating indicated on the
name plate of the instrument.

5. Setup

During the start-up of the compressor the nominal voltage must not
drop below the values specified in the ‘Technical data‘.
Please note that the compressor requires a start-up current be­tween 45 and 50 A.
Therefore, the electric circuit at the installation site must be in­spected by an electrical engineer to ensure that it meets the re­quirements for a smooth operation of the instrument.
A constant adequate power supply to the instrument must be en­sured at all times.
Failure to comply with the above will cause severe damage to the
instrument.

Leica CM1850 – Cryostat

• Place the storage shelves in the cryochamber.

• Place the section waste tray and brush shelf in the cryochamber.

• Place the knife holder base on the microtome base plate.

• Insert the knife holder and clamp it on the base plate For details, please
refer to the separate instruction manual for your knife holder).

• Open the knife box with the knife and place it in the cryochamber for
precooling.

• Place all tools needed for specimen preparation in the cryochamber.

• Close the sliding window.

• Connect the mains plug to the mains power outlet at the wall.

17

5. Setup

5.3 Leica CM1850 - Overview

17

13

15

4

16

21

Fig. 6

18

20

8

13

12

19

18

10

14

9

13

11

Instruction Manual V 2.2 – 12/2003

5. Setup

3

5

6

1 Cryostat CM1850
2 Waste container
3 Control panel 1
4 Control panel 2
5 Storage shelf, left
6 Storage shelf, right
7 Automatic mains fuse
8 Support for stationary heat

7

extractor (accessory)*

9 Quick freeze shelf
10 Peltier element (accessory)
11 Parking station (accessory)*
12 Stationary heat extractor

(accessory)*

13 Specimen disc
14 Thermal bloc (accessory)
15 Section waste tray
16 Brush shelf
17 Orientable specimen head

2

1

18 Knife holder base (accessory)
19 Knife holder CE (accessory)
20 Knife holder CN (accessory)
21 Knife holder CS (accessory)

Leica CM1850 – Cryostat

*) included in the standard delivery

range of models with Peltier
element

19

5. Setup

5.4 Mains switch and automatic mains fuse

The automatic mains fuse is used as mains switch.
To turn the automatic mains fuse on, the switch must be set in the upper
position (pos. 1).
To turn the automatic mains fuse off, the switch must be set in the lower
position (pos. 0).

Fig. 7
Automatic mains fuse

5.5 Turning the instrument on

After transporting, wait at least 4 hours before turning the instru­ment on.
This waiting period is necessary to allow the compressor oil,
which may have been displaced during transport, to return to its
original position.
Failure to comply with this can cause severe damage to the instru­ment.

20

• Turn the instrument on with the automatic mains fuse.

• The instrument has been configured ex works as follows:

Time: 00:00
Defrost time: 10:00
Cryochamber cooling: On

(Indication of the temperature)

Peltier element (option): Off

Indication ‘PE‘

without Peltier element: Indication ‘LL‘

• Set the desired values as described in the sections 6.2.1 to 6.2.3.

During normal operation pressure compensation prior to the com­pressor start-up might lead to a hissing sound.

Instruction Manual V 2.2 – 12/2003

6.1 Control panel 1

Fig. 8

6. Control panel operation

Function keys

Lamp button
ON/OFF switch for cryochamber illumination.

Manual defrost button
To activate and deactivate manual defrosting.

Key button
To lock and unlock the control panel to protect the entered parameters from
unintended modifications. To lock or unlock, hold down for approximately 5
seconds.

6.2 Programming the desired values

6.2.1 Setting the time

The actual time is set on the panel marked with the clock symbol using the
and keys.
When pushing the or button for more than 1 second, the time value
increases or decreases continuously (autorepeat function).



Fig. 9

Leica CM1850 – Cryostat



21

6. Control panel operation

6.2.2 Setting the automatic defrost time (cryochamber)

The automatic defrost cycle takes place once within 24 hours.
Touch the or button for indication of the beginning of the defrost cycle
which has actually been set. At the same time, the LEDs between the indi­cation of hours and minutes are flashing.
To change the beginning of the defrost cycle in steps of 15 minutes, push

Fig. 10



6.2.3 Selecting the cryochamber temperature

Fig. 11

the or button.



The temperature of the cryochamber is set and indicated on the panel marked
with the cryostat symbol.
The actual temperature is the standard indication.
For indication of the desired value, touch the or button.
Set the desired value with the and buttons. When pushing the or
bu tton for more than 1 second, the chamber temperature value increases
or decreases continuously.
The actual value will be indicated 5 seconds after finishing the program­ming.

22

Instruction Manual V 2.2 – 12/2003

6.2.4 Activation of the Peltier element (option)

The Peltier element is used for cooling the quick-freeze stations. Upon acti­vation of the Peltier element, the compressor of the cooling system is started
after 40 seconds to reinforce the thermal conductivity effect.
Display reading of instruments

without Peltier element: ‘LL‘

Fig. 12

with Peltier element: ‘PE‘
The Peltier element is activated by pressing .
Once activated, the display indication changes to ‘10‘ (i.e. the Peltier ele­ment will operate for 10 minutes). The countdown of the remaining cooling
time is permanently displayed.

The Peltier element turns off automatically after 10 minutes.
Once the remaining cooling time displayed is 4 minutes, the figure 4 is fol­lowed by a point (‘ 4. ‘). At this stage the Peltier element may be deactivated
by pressing again.
Once deactivated, the display indication returns to ‘PE‘.

6.2.5 Manual defrosting of the quick freeze shelf

6. Control panel operation

Fig. 13

Leica CM1850 – Cryostat

The quick freeze shelf may become hot during defrosting!
Therefore, do not touch it!

The manual defrosting of the quick freeze shelf is activated by subsequently
pressing the button (audible signal turns on) and the key (audible
signal turns off). During the defrost cycle, the indication is flashing.
To turn off the manual defrosting cycle of the quick freeze shelf prior to the
automatic deactivation, press again and .

Quick freeze shelf and cryochamber defrosting can be run inde­pendently. However, it is not possible to defrost both systems si­multaneously.

23

6. Control panel operation

6.2.6 Manual defrosting of the cryochamber

The manual defrosting of the cryochamber is activated by subsequently
pressing the button (audible signal turns on) and the or button on
the panel for the cryochamber temperature (audible signal turns off). During
the defrost cycle, the indication is flashing.
If you want to turn off the manual defrosting of the quick freeze shelf prior to
the automatic deactivation, press again and or on the panel for
the cryochamber temperature.

Fig. 14



6.3 Display lock



The programmed values cannot be modified after having pushed the key
button.

Push the key button once more for 5 seconds to unlock the display.

Fig. 15

24

When the display is locked, the LEDs between the hour and minute indica­tion on the time panel are turned off.

Instruction Manual V 2.2 – 12/2003

6.4 Control panel 2 - Electric coarse feed

Move the specimen away from the knife

• Press to start a rapid return travel of the specimen to the rear limit.
LED (1) flashes, while the specimen head is in motion.

6. Control panel operation

1

On reaching the rear limit, the LED (1) starts illuminating.

• The return movement can be stopped by pressing one of the coarse feed
buttons.

• Press to start a slow return movements of the specimen to the rear limit.

The specimen will slowly move to the rear limit, as long as the button is
held down.

Move the specimen towards the knife

• Press to start a rapid or slow advance of the specimen towards the knife.

The advance movement operates as long as the button is pressed. This

rapid

2

slow

is a safety feature to protect both the specimen and knife from damage!

On reaching the front limit, the LED (2) of the button starts illuminating.

Leica CM1850 – Cryostat

25

7. Daily use of the instrument

7.1 Specimen freezing

• Select the appropriate sectioning temperature (cryochamber tempera­ture) for the sample material (please refer to 7.4 Temperature selection

chart‘).

7.1.1 Quick freeze shelf

The cryochamber has a quick freeze shelf (5, Fig. 17) for up to 10 specimen discs.
The temperature of the quick freeze shelf is always lower than the cryochamber

1

temperature.

2

5

• Cut the specimen to size.

• Activate the Peltier element (4) (option), if
available - it may take up to 40 seconds until
the maximum refrigeration output is available.

• Apply enough cryocompound to a specimen
disc at room temperature.

• Place the specimen on the disc and orient.

• Place the specimen disc in one of the holes of
the quick freeze shelf and freeze the specimen
at a low temperature.

• Once the specimen is frozen, insert the
specimen disc in the specimen head
(Fig. 18) and start sectioning.

Fig. 17

4

3

7.1.2 Stationary heat extractor (accessory)*

• Fix the support (1) of the heat extractor (2) by tightening the 2 screws to
the threaded holes on the left sidewall of the cryochamber and insert the
heat extractor.

• Lower the heat extractor cylinder on the specimen surface. After ap­proximately 30 seconds contact, the specimen will be entirely frozen.

• Once the specimen is frozen, place the heat extractor on the parking
station (3).

*) included in models with Peltier element

26

Instruction Manual V 2.2 – 12/2003

7. Daily use of the instrument

7.2 Specimen discs 7.2.1 Inserting the specimen discs in the
specimen head

• Lock the handle of the handwheel in the upper
position.

• If the knife holder and a knife are in place,
cover the knife edge with the knife guard.

• Loosen the screw (1) on the specimen head.

• Insert the shaft of the specimen disc (3) in the
location hole (2) of the specimen head.

Make sure that the shaft of the specimen disc is
fully inserted. The entire rear surface of the prism
must have a good contact with the specimen
head.

Fig. 18

• Retighten screw (1).

7.2.2 Specimen orientation

• To release, loosen screw (4).

• Orient the specimen surface with lever (5).

• Retighten screw (4).

Leica CM1850 – Cryostat

27

7. Daily use of the instrument

7.3 Sectioning

All necessary adjustments on the knife holder and anti-roll guide
are described in the separate instruction manual for your knife
holder in detail.

7.3.1 Trimming the specimen

Take care when handling microtome knives and disposable
blades. The cutting edge is extremely sharp and can cause severe
injury!

• Insert the precooled knife/blade in the knife holder and clamp.

• Adjust the appropriate clearance angle on the knife holder. Adjustments between 4 ° and 6 ° (knife
holder CN and CS) or between 1 ° and 2 ° (knife holder CE) are suitable for most applications.

• Align the knife holder/knife with the specimen.

• Remove the knife guard (knife holder CN, CS) or fold the glass anti-roll guide (knife holder CE) over
to the left.

• Unlock the handwheel.

• Trim the specimen to shape approach the specimen towards the knife by means of the coarse feed
buttons. Trim the specimen down to the required sectioning plane by turning the handwheel.

• Position the anti-roll guide on the knife and align with the cutting edge.
Readjust the anti-roll plate if necessary.

7.3.2 Section thickness setting

The section thickness is adjusted in a range of 1 to 60 µm by turning the knob

(1) :

f rom 0 - 10 µm in 1 µm increments,
from 10 - 20 µm in 2 µm increments, from 20 - 60 µm in 5 µm increments.
The selected section thickness is indicated on the index mark on the
microtome.

• Select the required section thickness with the control knob on the

microtome.
Start sectioning at approximately 20 µm.

• Decrease the section thickness continually down to the appropriate value.
After changing from one section thickness to another, the first two or three sections should
berejected.

• When sectioning, turn the handwheel at a constant speed.

28

Instruction Manual V 2.2 – 12/2003

7. Daily use of the instrument

7.4 Temperaturew selection chart (in minus °C)

Tissue -10°C – -15°C -15°C – -25°C -25°C – -35°C

Adrenal ❄❄
Bone marrow ❄
Brain ❄
Bladder ❄
Breast - fatty ❄
Breast - little fat ❄
Cartilage ❄❄
Cervical ❄
Fatty ❄
Heart and vascular ❄
Intestinal ❄
Kidney ❄
Laryngeal ❄
Lip ❄
Liver ❄
Lung ❄
Lymphoid ❄
Muscular ❄
Nose ❄
Pancreatic ❄
Prostate ❄
Ovarian ❄
Rectal ❄
Skin with fat ❄
Skin without fat ❄
Spleenal or bloody tissue ❄
Testicular ❄❄
Thyroid ❄
Tongue ❄
Uterus curettage ❄

The temperature values given above are based on long-term experience, however, these are only approximate values,
as any tissue may require particular adjustments.

Leica CM1850 – Cryostat

29

7. Daily use of the instrument

7.5 Defrosting

Defrosting the cryochamber actually means defrosting the evaporator to
prevent excessive frost buildup. The evaporator is flushed with hot gas dur­ing defrosting. The cryochamber virtually is frostfree and does not need to
be defrosted.
The condensation water that is produced during defrosting is collected in a
container, which is located at the front of the cryostat cabinet.

To make sure that the condensation water stemming from the de­frost cycles drains into the waste container and to avoid the risk of
possible contaminations, ensure that the tap of the waste con­tainer (2, Fig. 41) is open when operating the instrument. Only
shut the tap when draining the waste container!

The quick freeze shelf is cooled during the automatic cryochamber
defrosting. However, the Peltier element is turned off.The maxi­mum duration of a defrost cycle is 12 minutes. Defrosting is termi­nated automatically once the cryochamber has reached a tem­perature of -5 °C.
Cooling turns back on automatically.

7.5.1 Automatic defrosting of the cryochamber

An automatic defrost cycle takes place once in 24 hours.
The time of the automatic defrost cycle is programmed via the control panel
1 (see 6.2.1 and 6.2.2).

7.5.2 Manual defrosting of the cryochamber

In addition to the programmable automatic defrost cycle a manual defrost
cycle can be activated (see also 6.2.6).

To avoid an unintended defrosting, the activation of a manual de­frost cycle is confirmed by an audible signal.
Cooling turns back on automatically.

30

Instruction Manual V 2.2 – 12/2003

7.5.3 Manual defrosting of the quick freeze shelf

The quick freeze shelf may become hot during defrosting!
Therefore, do not touch it!

If increased frost formation occurs on the quick freeze shelf, especially af­ter spray disinfection, a manual defrost cycle should be started (see 6.2.5),
which can be terminated when required.

7.6 Terminating work

7.6.1 Terminating daily work

• Lock the handwheel.

• Take the knife out of the knife holder and put it back into the knife box in
the cryochamber.

• Remove frozen section waste with a cold brush.

• Empty the section waste tray.

• Clean the storage shelves and brush shelf.

7. Daily use of the instrument

Leica CM1850 – Cryostat

Only common detergents and disinfectants that contain 95 - 98%
alcohol should be used for cleaning.
All components removed from the cold environment will collect
condensation. Therefore, dry them thoroughly before placing them
back into the cryochamber.

• Remove all specimens from the cryostat.

• Close the sliding window.

• Turn out the cryochamber illumination.

• Lock control panel 1 (Fig. 8) with the KEY button.

• Do not turn the instrument off with the automatic mains fuse as there
would be no cooling.

31

8. Troubleshooting

7.6.2 Shutdown for a longer period

If you do not intend to use the instrument for several weeks you
may turn it off.
Please note, however, that it may take up to several hours to cool
the cryochamber down to very low temperatures after turning the
instrument on again.
After turning off, the instrument should be cleaned and disinfected
thoroughly (see chapter 9 ‘Cleaning, disinfection and mainte­nance').

• Turn the instrument off with the automatic mains fuse.

• Open the sliding window to allow the cryochamber to dry.

• Remove all the specimens from the cryostat.

• Lock the handwheel.

• Take the knife/blade out of the knife holder. Put the knife back into the
knife box or push the blade into the receptacle for used blades provided
at the bottom of the dispenser.

• Remove all section waste with a cold brush.

• Empty the section waste tray and remove it for cleaning and disinfec­tion.

• Remove the storage shelves and the brush shelf for cleaning and disin­fection.

Turning off the instrument with the automatic mains fuse will not affect the
programmed parameters.

Before turning the instrument on again, the cryochamber microtome and all
accessory components must be absolutely dry.

32

Instruction Manual V 2.2 – 12/2003

8. Troubleshooting

8.1 Error messages in the display

Error messages are displayed on the clock panel as follows: EO: XX. The
following error messages might occur during operation:

Fig. 20

Error Description Remedy

20 Calibrating error; possibly defective controller board. Turn the instrument on again.

If the error is displayed again:

Call service.
21 Clock battery on the controller board empty. Call service.
22 Microtome wet. Dry microtome.
23 Cryochamber temperature out of range of indication. Remove cause.

(from -35 °C to +55 °C)

24 Short circuit at the temperature sensor Call service.

of the chamber cooling system.

25 Breaking of the temperature sensor Call service.

of the chamber cooling system.
26 Short circuit at the temperature sensor of the evaporator. Call service.
27 Breaking of the temperature sensor of the evaporator. Call service.

8.2 Temperature control button

On the back of the cryostat cabinet there is a temperature control button (1). If the temperature of the
cryochamber exceeds 60 °C the switch is automatically activated and turns the instrument off.

Possible causes and remedies:

• Temperature of the direct surroundings is
constantly higher than 40 °C.

-->Drop the temperature of the direct sur­roundings.

• When setting up the instrument the minimum
distance of 10 cm to walls and furniture was
not kept.

--> Keep the minimum distance.

• The ventilation slits of the liquefier are dirty.

Fig. 21

After eliminating the possible source of error, push the temperature control button (1) to turn the in­strument back on. If the instrument fails to turn on, make a service call.

Leica CM1850 – Cryostat

--> Clean the ventilation slits (see 9.3.1).

33

8. Troubleshooting

8.3 Possible causes and remedies
Problem Cause Remedy

Frost on chamber walls and mi­crotome

Ice formation on the bottom of
the cryochamber

Sections smear

Sections splinter

Sections not properly flattened

- Cryostat is exposed to air cur­rents (open windows and
doors, air conditioning).

- Sliding window was open and
exposed to air currents too
long.

- Frost built up by breathing into
the cryochamber.

- Condensation water drain ob­structed.

- Drain of the quick freeze shelf
defrosting water obstructed.

- Specimen not cold enough.

- Knife/blade and/or anti-roll
plate not yet cold enough and
thus warm the sections.

- Specimen too cold

- Static electricity/air currents.

- Specimen not cold enough.

- Large area specimen.

- Anti-roll plate poorly posi­tioned.

- Anti-roll plate poorly aligned
with knife edge.

- Incorrect clearance angle.

- Knife/blade blunt or damaged.

- Change place of installation for
the cryostat.

- Open the tap of the drain tube
(2, Fig. 31), switch off the instru­ment and let it thaw and dry.

- Align the instrument with a
spirit level.

- Select lower temperature.

- Wait until knife/blade and/or
anti-roll plate have reached
chamber temperature.

- Select higher temperature.

- Remove cause.

- Select lower temperature.

- Trim the specimen parallel,
increase section thickness.

- Reposition anti-roll plate.

- Align correctly.

- Set correct angle.

- Use different part of the cutting
edge or replace.

34

Instruction Manual V 2.2 – 12/2003

8. Troubleshooting

Problem Cause Remedy

Sections not properly flattened
despite correct temperature and
correctly aligned anti-roll plate

Sections curl on the anti-roll
plate

Scraping noise during sectioning
and specimen return movement

Ridged sections

Chatter during sectioning

- Knife/blade and/or anti-roll
plate dirty.

- Edge of anti-roll pate damaged.

- Blunt knife/blade.

- Anti-roll plate does not pro­trude far enough beyond the
cutting edge.

- Anti-roll plate protrudes too far
beyond the cutting edge and is
scraping against the specimen.

- Knife/blade damaged.

- Edge of anti-roll plate dam­aged.

- Specimen insufficiently frozen
onto the specimen disc.

- Specimen disc not clamped
tightly.

- Specimen holder ball joint not
clamped.

- Knife/blade not clamped tightly
enough.

- Specimen has been sectioned
too thickly and has detached
from the disc.

- Very hard, inhomogeneous
specimen.

- Blunt knife/blade.

- Clean with dry cloth or brush.

- Replace plate.

- Use different part of the cutting
edge or replace.

- Readjust correctly.

- Readjust correctly.

- Use different part of the cutting
edge or replace.

- Replace the plate.

- Refreeze specimen onto the
disc.

- Check disc clamping.

- Check ball joint clamping.

- Check knife/blade clamping.

- Refreeze specimen onto the
disc.

- Increase section thickness;
reduce specimen surface area
if necessary.

- Use different part of the cutting
edge or replace the knife/
blade.

Leica CM1850 – Cryostat

35

8. Troubleshooting

Problem Cause Remedy

Condensation on anti-roll plate
and knife during cleaning

Anti-roll plate damage after ad­justment

Thick-thin sections

- Knife profile inappropriate for
the specimen to be cut.

- Incorrect clearance angle.

- Brush, forceps and/or cloth are
too warm.

- Plate too high above the cut­ting edge. The adjustment was
carried out in the direction of
the cutting edge.

- Temperature incorrect for the
tissue cut.

- Knife profile inappropriate for
the specimen cut.

- Ice buildup in the knife back.

- Handwheel speed not uni­form.

- Knife/blade not clamped tightly
enough.

- Specimen holder not clamped
tightly.

- Cryocompound applied to cold
specimen disc; specimen de­tached from the disc after
freezing.

- Blunt cutting edge.

- Incorrect clearance angle.

- Microtome not properly dried
before reinstallation.

- Dried specimen.

- Use knife with different profile.

- Set correct angle.

- Store all tools on shelf in the
chamber.

- Raise plate when aligning.

- Be more careful next time.

- Select correct temperature.

- Wait until the correct tempera­ture is reached.

- Use knife with different profile
(c or d).

- Remove ice.

- Adapt speed.

- Check knife/blade clamping.

- Check clamping.

- Apply cryocompound on warm
disc; mount specimen and
freeze.

- Use different part of the cutting
edge or replace the knife/
blade.

- Set correct angle.

- Dry microtome thoroughly.

- Prepare new specimen.

Tissue sticks or crumbles on the
anti-roll plate

36

- Anti-roll plate is too warm or
incorrectly positioned.

- Static electricity.

- Cool down anti-roll plate or
reposition plate.

- Remove static electricity.

Instruction Manual V 2.2 – 12/2003

8. Troubleshooting

Problem Cause Remedy

Flattened sections curl up when
anti-roll plate is picked up

Sections tear

Inconsistent or insufficient speci­men feed

Specimen disc cannot be re­moved

Fat on the corner or edge of the
anti-roll plate.

- Rusty knife/blade.

- Static electricity or air cur­rents.

- Anti-roll plate too warm.

- Temperature too low for the
tissue cut.

- Blunt part, dirt, dust, frost or
rust on the knife/blade.

- Leading edge of anti-roll plate
damaged.

- Hard particles in the tissue.

- Knife back dirty.

- Microtome was not entirely dry
when switching on refrigera­tion; consequently ice built up
in the micrometer feed system.

- Defective microtome.

- Moisture on the underside
caused the disc to freeze to the
freezing shelf or specimen
head.

- Remove fat with alcohol.

- Remove rust.

- Remove static electricity.

- Cool down the anti-roll plate.

- Increase temperature and
wait.

- Remove cause.

- Replace the plate.

- - -

- Clean.

- Remove the microtome and
dry it thoroughly before rein­stallation.

- Call technical service.

- Apply concentrated alcohol to
the contact point or heat the
specimen head.

Cryostat inoperational

Leica CM1850 – Cryostat

- Mains plug not properly con­nected.

- Defective fuses.

- Temperature control switch
activated.

- Check the mains plug is prop­erly connected.

- Replace the fuses.

- Check site conditions as de­scribed in section 5.2, and
reset the temperature control
switch.

37

8. Troubleshooting

Problem Cause Remedy

No or insufficient refrigeration

Scraping noise at the microtome

- Compressor defective.

- Leak in the cooling system.

- Inappropriate site conditions.

- Ventilation slits of the liquefier
dirty.

- Friction between the slot cover
and the microtome housing.

- Call technical service.

- Call technical service.

- Check site conditions as de­scribed in section 5.2.

- Clean the ventilation slits as
described in section 10.3.1.

- Apply cryostat oil to the slot
cover and distribute by turning
the handwheel or with a cloth.

38

Instruction Manual V 2.2 – 12/2003

9.1 Cleaning

2

3

9. Cleaning, disinfection, maintenance

• Remove frozen section waste from the cryostat with a cold brush every
day.

• Remove the section waste tray for emptying.

• Remove the storage shelves and the brush shelf for cleaning.

• Remove the sliding window by slightly lifting and pulling it to the front
when closed (see 9.3.6 'Replacement of the lamp').

Do not use organic solvents or any other aggressive substances for
cleaning and disinfecting! Only use the cleaning agents specified
in this instruction manual such as Leica Cryofect (alcohol or com­mon disinfectants based on alcohol)!

• Drain the cleaning liquid through the hose after the prescribed reagent
time is over and collect it in the waste container (1).

• Dispose of the waste liquid according to the
waste disposal regulations.

• To remove the waste container (1), shut off the
tap (2) and unscrew the lid (3).

1

Leica CM1850 – Cryostat

Fig. 22

Condensation water produced during defrosting collects in the
waste container. Therefore, check the liquid level regularly and
empty the container if necessary.

39

9. Cleaning, disinfection, maintenance

9.2 Spray disinfection with Leica Cryofect

For easy-to-use spray disinfection we recommend Leica Cryofect.
The cryostat has to be disinfected after each daily use.

Comply with the instructions for use!
The glass anti-roll plate can remain in place during disinfection.

1. Select a cryochamber temperature value down to -20 °C.

2. Remove the knife or blade from the knife holder.

3. Remove all samples, microscope slides and tools from the cryochamber.

4. Remove debris from the cryochamber.

Allow the cryochamber to reach the previously selected temperature.
Once the selected temperature is reached, either

5a. spray the disinfectant evenly on the contaminated surfaces- the sur-

faces should be covered with an even layer - or

40

5b. soak a cloth with disinfectant and apply it on the contaminated surfaces.

6. Allow a reaction time of no less than 15 minutes.

7. Wipe it off with a tissue.

8. Dispose of tissue in compliance with the ruling waste disposal regula­tions of your institution.

9. Set the cryochamber temperature to the originally selected value.

If increased frost buildup occurs, start a manual defrost cycle.

Instruction Manual V 2.2 – 12/2003

9. Cleaning, disinfection, maintenance

9.3 Maintenance 9.3.1 General maintenance

1

The microtome is virtually maintenance-free. To
ensure a smooth operation of the instrument over
several years we recommend the following:

4

2

3

• Have the instrument inspected by a qualified
service engineer authorized by us once a year.

• Enter into a service contract at the end of the
warranty period.
For further information, please contact your
local Leica service center.

• Clean the instrument every day.

Fig. 23

Once a week:

• Apply a drop of oil to the plastic coupling (5,
Fig. 26).

• Lubricate the specimen cylinder (1):
Push the appropriate coarse feed button to
move the specimen cylinder out to the front
stop position, apply a drop of cryostat oil and
move the specimen cylinder back to the home
position by pressing the appropriate coarse
feed button.

Fig. 24

Leica CM1850 – Cryostat

Occasionally, or when required:

5

• Lubricate the clamping piece (T-piece) (2) on
the microtome base plate and the clamping
lever (3).

• Lubricate the slot cover (4).
To do so, turn the handwheel to place the
specimen head to the uppermost position and
apply some drops of cryostat oil on to the slot
cover; after that place the specimen head to

41

9. Cleaning, disinfection, maintenance

the lowest position and apply some drops of cryostat oil on to the slot
cover; distribute the applied oil by turning the handwheel or with a soft
tissue.

• Clean the ventilation slits (5) of the liquefier on the right side of the instru-
ment with a brush, broom or vacuum cleaner from dust and dirt in the
direction of the fins.

• Do not carry out any repairs on your own as this will invalidate the war­ranty.
Repairs may only be carried out by qualified service engineers autho­rized by Leica.

The microtome can be removed for thorough cleaning and disin­fecting, or for extensive drying after a long power failure!

9.3.2 Removal of the microtome

Turn the instrument off and disconnect the mains plug before re­moving the microtome.
Prior to removing the microtome, place the specimen head to the
lowest position by placing the handle of the handwheel in the low­est position.
When removing the microtome, the specimen head will rapidly fall
down and might injure the operator‘s hands.
Wear appropriate protective gloves to take the cold microtome out
of the cryochamber!
Extended skin contact with cold parts of the instrument may cause
frost bite!

42

• Slightly lift the sliding window when closed holding it at the grip provided
and pull it out to the front (Fig. 30) - see ‘9.3.6 Replacement of the

lamp‘.

• Remove the accessories in the following order: brush shelf, knife holder,
section waste tray, specimen discs, stationary heat extractor, left stor­age shelf, right storage shelf.

Instruction Manual V 2.2 – 12/2003

9. Cleaning, disinfection, maintenance

1

Fig. 25

2

4

• Loosen the screws (3) with an Allen key (4 mm).

Do not loosen the screws (7) for removing the
microtome.

• Disconnect the coarse feed motor plug (1) by
pulling the metal head.

• Disconnect the temperature sensor (2) from

3

8

8

7

the microtome.

Leica CM1850 – Cryostat

5

• Slightly lift the microtome and pull it to the left
to disengage the plastic coupling (5)
connecting the axes.

• Take the microtome out of the cryochamber.

Fig. 26

43

9. Cleaning, disinfection, maintenance

9.3.3 Removal of the microtome cover

8

8

8

Fig. 27

The microtome cover may be removed
to expeditethorough drying of the mi­crotome in an oven. Note:
Place the microtome in an oven at 40
°C to 50 °C for several hours.
After repeatedly drying the microtome
in this manner, it may become neces­sary to relubricate the cross roller
bearings!
For further information, please contact
your sales company!

• Loosen the two screws (8) on both sides of the

8

cover.

• To remove, pull the cover upwards. The front
plate of the microtome with the specimen head
remains in place.

Do not use external heaters for drying
the cryochamber!
This can cause damage to the cooling
system!

9.3.4 Reinstallation of the microtome

• Place the microtome slightly left from the original position into the
cryochamber. Make sure that the specimen head is in the lowest posi­tion.

• Lubricate the surface of the plastic coupling (5) with a drop of cryostat
oil.

• Mount the plastic coupling (5) on the shaft (4).

• Use your right hand to bring the handwheel handle in the lowest position
and keep the handle in place. The specimen head remains in the lower
position.

44

Instruction Manual V 2.2 – 12/2003

9. Cleaning, disinfection, maintenance

Ensure that the microtome is completely dry before reinstallation.
Humidity inside will condense and freeze and thus cause malfunctions or damage to the feed
system of the microtome.

• Use your right hand to bring the handwheel handle in the lowest position

and keep the handle in place. The specimen head remains in the lower
position.

• Push the microtome to the right with your left hand, and, if necessary,

turn the handwheel back and forth to ensure proper alignment of the
parts until the plastic coupling (5) engages to the shaft (6).

• Tighten the screws (3).

• Reconnect the coarse feed motor plug (1) and the temperature sensor

(2).

• Replace the storage shelves, heat extractor, brush shelf and knife holder

in the cryochamber.

2

1

Fig. 28

Leica CM1850 – Cryostat

• Replace the sliding window.

4

3

Fig. 29

5

6

Ensure that all components removed
from the cold environment are com­pletely dry before placing them back
into the cryochamber.

45

9. Cleaning, disinfection, maintenance

9.3.5 Replacement of the fuses

Turn the instrument off with the automatic mains fuse and pull the
mains plug, before replacing the fuses!
Only use fuses of the same specification! For the required values,
please refer Chapter 3 ‘Technical Data‘. The use of fuses other than
specified by the manufacturer may cause severe damage to the in­strument!

Fig. 29

Fuse Protection Type

F1 Display T 0.25 A
F2 Coarse feed T 0.6 A
F3 Processor board supply T 1.6 A
F4 Peltier element T 6.25 A
F5 Heaters T 4 A

On the back of the instrument there is a fuse box
with 5 fuses:

• Unscrew the fuse cap with a screwdriver.

• Remove both fuse cap and fuse.

• Put the new fuse in the cap and screw the fuse
cap back on.

9.3.6 Replacement of the lamp

46

Turn the instrument off with the automatic mains fuse and pull the
mains plug, before replacing the lamp!
If the lamp is broken, it must be replaced by the technical service,
as the replacement involves a high risk of injury.

Instruction Manual V 2.2 – 12/2003

1

Fig. 30

9. Cleaning, disinfection, maintenance

• Turn the instrument off with the automatic

mains fuse.

• Pull the mains plug.

• Slightly lift the sliding window (1) holding it by

the grip (2) and pull it out to the front.

• For the technical specification of the lamp,

please refer to Chapter 4. ‘Technical data‘.

2

Fig. 31

Fig. 32

45

3

6

Removal of the lamp

The lamp (3) is mounted behind a glare shield (4)

and therefore not visible.

• Touch the lamp for better orientation.

• Lightly tilt the fluorescent tube down to the left

and pull it out of the clip (5).

• Hold the lamp with both hands and pull it to

the left out of the holder (6).

Installation of the new lamp

• Hold the lamp in the correct mounting position

as shown (Fig. 32) and push it to the right
until it engages in the holder.

• Lightly push the fluorescent tube upward to

engage in the clip.

• Replace the sliding window.

• Reconnect the instrument to the mains power

and turn it on.

Leica CM1850 – Cryostat

47

10. Ordering information, optional accessories

10.1 Ordering information

Knife holders

Knife holder CN for standard knives
for reusable knives or the magnetic blade rail for disposable blades,
with anti-roll guide, adjustable knife guard and knife support bars 0419 18649
Knife support bar for knife holder CN, for slim knives 0419 19426
Knife support bar for knife holder CN, for broad knives 0419 19427

Knife holder CE for low profile disposable blades with glass anti-roll guide 0419 30383
Knife holder CE for high profile disposable blades with glass anti-roll guide 0419 30390

Knife holder CS for reusable knives and Cryolap disposable blades,
with one knife support (to be positioned on the left or right), anti-roll guide, knife guard 0419 19787
Auxiliary clamping device for knife holder CS 0419 20971

Knife support bar for knife holder CS 0419 25681
Knife holder base for the knife holders CN, CE and CS 0419 26140
Knife rest with section collecting tray for knife holder CS 0419 18996

Specimen discs

Specimen disc, 20 mm ø 0370 08636
Specimen disc, 25 mm ø 0416 19275
Specimen disc, 30 mm ø 0370 08587
Specimen disc, 40 mm ø 0370 08637
Specimen disc, 55 mm ø 0419 26491

Accessories

Stationary heat extractor with support * 0471 30792
Parking station * 0471 30793
Mobile heat extractor * 0443 26836
Thermal bloc to remove frozen specimens from the cold specimen disc 0398 18542
Glass anti-roll guide, complete assembly, for knife holder CE 0419 30402
Glass anti roll-guide upgrade kit, for retrofitting knife holders CN, CS (for C-profile knives) 0419 30403

Consumables

OCT cryocompound, bottle of 125 ml 0201 08926
Cryostat oil No. 407, bottle of 100 ml 0336 06099
Leica Cryofect Spray disinfectant 0387 30795

* included in standard delivery on models with Peltier element

48

Instruction Manual V 2.2 – 12/2003

10.2 Optional accessories

10.2.1Mobile heat extractor

Specimen freezing with the freezing shelf can be accelerated by the addi­tional use of a heat extractor.

• Store the heat extractor in the cryochamber.

• Place it on the specimen surface to accelerate freezing.

• Remove it once the specimen is entirely frozen.It is recommended to

10. Ordering information, optional accessories

precool the heat extractor in liquid nitrogen or other refrigerant.

Fig. 33

10.2.2Thermal block

5
6

7

8

It is recommended to precool the heat extractor in liquid nitrogen
or other refrigerant.

The thermal block (8) facilitates the removal of the frozen specimen from the
specimen disc.

Keep the thermal block outside the cryochamber at room tempera­ture. Place it in the cryochamber only for specimen removal.

• Place the cap (9) on the required side, so that the appropriate location
hole for the specimen disc is visible.

• Insert the shaft (6) of the specimen disc (5) in the appropriate location
hole (7) at the top or bottom of the thermal block.

• After about 20 seconds, the frozen specimen can be removed from the
specimen disc with forceps.

• If the cap is too loose, readjust it with the small screw (10). Do not over-
tighten the screw.

• Once the specimen is removed, take the thermal block out of the cold
cryochamber.

9

Fig. 34

Leica CM1850 – Cryostat

10

49

11. Warranty and service

Warranty

Leica Microsystems Nussloch GmbH guarantees that the contractual prod­uct delivered has been subjected to a comprehensive quality control proce­dure based on the Leica in-house testing standards, and that the product is
faultless and complies with all technical specifications and/or agreed char­acteristics warranted.

The scope of the warranty is based on the content of the concluded agree­ment. The warranty terms of your Leica sales organization or the organiza­tion from which you have purchased the contractual product shall apply
exclusively.

Technical service information

If you require technical service or replacement parts, please contact your
Leica sales representative or dealer who sold the product.

Please provide the following information:

• Model name and serial number of the instrument.

• Location of the instrument and name of the person to contact.

• Reason for the service call.

• Date of delivery.

Decommissioning and disposal

The instrument or parts of the instrument must be disposed of in compliance
with the local laws.

50

Instruction Manual V 2.2 – 12/2003