Bio-Rad 785 Instruction manual

Model 785

Vacuum Blotter

Instruction

Manual

For Technical Service

Call Your Local Bio-Rad Office or

in the U.S. Call 1-800-4BIORAD

(1-800-424-6723)

Table of Contents

Section 1 General Information............................................................................................. 1

1.1 Safety/Definition of Symbols.................................................................................... 1

1.2 Introduction to Model 785 Vacuum Blotter............................................................... 1

1.3 List of Parts................................................................................................................1

1.4 Features.....................................................................................................................1

1.5 Specifications............................................................................................................ 2

Section 2 Description of Major Parts.................................................................................. 3

2.1 Base Unit................................................................................................................... 3

2.2 Vacuum Stage........................................................................................................... 3

2.3 Porous Vacuum Plate................................................................................................ 3

2.4 Window Gasket......................................................................................................... 3

2.5 Sealing Frame........................................................................................................... 4

2.6 Vacuum Regulator..................................................................................................... 4

2.7 Vacuum Pump........................................................................................................... 4

2.8 Lid............................................................................................................................. 4

Section 3 Operating Instructions........................................................................................ 5

3.1 Vacuum Blotter Setup............................................................................................... 5

3.2 Preparation for Vacuum Transfer.............................................................................. 5

3.3 Gel Pretreatment........................................................................................................ 5

3.4 Vacuum Transfer....................................................................................................... 7

3.5 Post Transfer............................................................................................................. 8

Section 4 Cleaning and Maintenance.................................................................................... 8

4.1 Cleaning.................................................................................................................... 8

4.2 Replacement Parts..................................................................................................... 8

Section 5 Troubleshooting Guide....................................................................................... 9

5.1 Operational Troubleshooting..................................................................................... 9

5.2 Southern Hybridization Troubleshooting................................................................ 10

5.3 Repairing Cracked Gels.......................................................................................... 11

Section 6 Equipment and Accessories............................................................................. 12

6.1 Model 785 Vacuum Blotter and Accessories.......................................................... 12

6.2 Electrophoresis Reagents........................................................................................ 12

6.3 Electrophoresis Units.............................................................................................. 13

6.4 Blotting Reagents..................................................................................................... 13

Section 7 Appendix........................................................................................................... 14

7.1 Facts About Vacuum Transfer................................................................................. 14

7.2 Required Solutions and Equipment......................................................................... 16

Section 1
General Information

1.1 Safety/Definition of Symbols

Caution

This instrument is intended for laboratory use only.

This product conforms to the “Class A” standards for electromagnetic emissions intended for
laboratory equipment applications. It is possible that emissions form this product may interfer
with some sensitive appliances when placed nearby or in the some circuit as those applicances.
The user should be aware of this potential and take appropriate measures to avoid interference.

1.2 Introduction to the Model 785 Vacuum Blotter

The Model 785 Vacuum Blotter is a nucleic acid transfer apparatus which rapidly transfers
DNA or RNA from agarose gels onto nylon membranes by using low vacuum. The Model 785
Vacuum Blotter simplifies every step of the blotting process. In addition, the Model 785 Vacuum
Blotter is constructed for long term heavy use. The following protocols have been thoroughly
tested and have the continuing technical support of Bio-Rad Laboratories.

1.3 List of Parts

Each Model 785 Vacuum Blotter unit comes with the items listed below. Check to make sure
that all components are present. Also note any damage to the instrument that may have occured
during shipping. Inform Bio-Rad Laboratories if any items are missing or damaged.

Item Quantity

Base Unit 1
Vacuum Stage 1
Porous Vacuum Plate 1
Window Gasket
– precut 15 x 15 cm 2
– precut 15 x 20 cm 2
– blank 2
Sealing Frame 1
Lid 1

Offered Accessories

Vacuum Regulator 1
Vacuum Station 1

1.4 General Description

The Vacuum Blotter has several innovative features which simplify the nucleic acid blotting
process and facilitate complete transfer. The Model 785 Vacuum Blotter features include:

• Easy-to-use spring latches which make assembly and disassembly quick. No screws or
nuts to tighten.

• Vacuum Stage and Porous Vacuum Plate create an even vacuum pressure throughout the

transfer area, providing even transfers and highly reproducible results.

• Large Vacuum Stage format permits large or small gel transfer using the blank Window

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Gasket or standard gel transfer using the precut Window Gasket.

• Green Window Gasket allows you to easily see the gel/gasket overlap for easy
alignment.

• Vacuum Regulator facilitates accurate vacuum pressure using Bio-Rad’s Vacuum
Pump or almost any vacuum source.

• Durable molded construction for long term heavy use.

• Base Unit and Sealing Frame designed for easy alignment of gel and membrane.

1.5 Specifications

Dimensions

Overall outer size 20” (L) x 12” (W) x 5” (H)
Gel capacity (maximum size) 20 cm x 25 cm

Unit weights

Complete assembly 8 lb
Lid weight 1.5 lb
Sealing frame assembly 1.5 lb
Porous vacuum support 0.25 lb

Materials

Base Mindel-S plastic
Springs Stainless steel
Posts Delrin plastic
Vacuum stage Mindel-S plastic
Window gasket Flexible green vinyl
Porous vacuum plate Polypropylene
Sealing frame Glass-filled Mindel-S
O-ring Silicone rubber
Lid Acrylic
Tubing Tygon (1/2” OD x 1/4” ID)

Vacuum regulator pump

Dimensions

Overall outer size 11” (L) x 6” (W) x 5” (H)

Weights

With pump 7.5 lb
Without pump 1.5 lb

Materials

Valve Polyvinylchloride
Fittings Nylon
Housing Acrylic
Interior pump components Teflon

Ratings

Vacuum pump 20 inches Hg (max)/250 Torr
Regulator 0-25 inches Hg (max)/125 Torr

Electrical

Input voltage range 100–120 VAC/50-60 Hz/1.5 A

220–240 VAC/50 Hz/0.75 A

Fuses

Internal Thermal Fuse

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Enviornmental

Operating 50 °F (10 °C) to 90 °F (32 °C) temperature

30–80% humidity

Storage 32 °F (0 °C) to 140 °F (60 °C) temperature

10–90% humidity

Cautions

1. Not designed to handle liquids or heavy vapors. If pump does get liquid inside, open
valve to max position and let run for 15 minutes to allow interior components to dry.

2. If valve knob loosens up during operation, wrap threads with teflon tape to increase
thread engagement.

3. Pump will become hot after a few hours of continuous use. This is normal and should
not be a cause for concern.

Section 2
Description of Major Parts

2.1 Base Unit

The Base Unit is the foundation of the Model 785 Vacuum Blotter. The plastic used to
make the Base Unit is an off-white color with a slight texture. The Base Unit is made of a
durable and chemically resistant mindel-S plastic. In low concentrations, acids and bases 0.25
N HCl or 0.5 N NaOH will not damage the Base Unit or the Vacuum Stage. The Base Unit
supports the Vacuum Stage on springs and catches the transfer solution during disassembly.

2.2 Vacuum Stage

The Vacuum Stage is supported by springs on the Base Unit. The spring action on
the Vacuum Stage is used to lock and unlock the Sealing Frame. The center portion of
the Vacuum Stage has a grooved grid pattern. This grid pattern helps distribute the
vacuum pressure evenly across the Porous Vacuum Plate. In the center of the grid pattern
is a port. This port is the vacuum inlet and is connected to vacuum tubing underneath the
Vacuum Stage. Surrounding the grid area is a soft silicon Reservoir Seal O-ring that
provides a water-tight seal to the upper buffer chamber.

2.3 Porous Vacuum Plate

The Porous Vacuum Plate is a white polypropylene sheet. The Porous Vacuum Plate
is used to support the transfer membrane and the gel. Along with the grid pattern on the
Vacuum Stage, the Porous Vacuum Plate helps distribute the vacuum pressure evenly.

2.4 Window Gasket

The Precut Window Gasket is a green vinyl sheet with a window cut out of the
center. Refer to Section 3.2 for instructions on how to cut the Blank Window Gasket. The
Window Gasket is used to mask off the remaining Porous Vacuum Plate not covered by
the gel. The Window Gasket forces the vacuum through the gel/membrane complex by
making a watertight seal where the gel overlaps the Window Gasket. The Window
Gasket also seals in the vacuum along the Reservoir Seal O-ring when the Sealing Frame
is compressed onto the Vacuum Stage.

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2.5 Sealing Frame

The Sealing Frame is made of the same mindel-S plastic as the Base Unit and has the
same off-white color as the Base Unit. The Sealing Frame features easy-to-use latches.
The latches will lock on to the post when the Sealing Frame is pressed onto the Vacuum
Stage. Simply press the latches inward to unlock the Sealing Frame. The Sealing Frame
compresses the Reservoir Seal O-ring onto the Window Gasket, creating an air-tight seal
between the Porous Vacuum Plate and the Window Gasket. The Sealing Frame also
holds the transfer solution over the gel during the transfer.

2.6 Vacuum Regulator

The Vacuum Regulator is used to control the vacuum pressure. There is a post on
either end of the Vacuum Regulator. One post is used for the vacuum source inlet and the
other post is used to connect the Model 785 Vacuum Blotter. The Vacuum Regulator has
a vacuum gauge attached to the center portion. Because the vacuum gauge is sensitive to
liquids, it is very important to connect a side-arm flask between the Vacuum Blotter and
the Vacuum Regulator. There is an adjustment valve in front of the pressure gauge.
Unscrewing the outer-most adjustment nut causes the vacuum pressure to decrease.
Screwing the adjustment nut clockwise increases the pressure.

2.7 Vacuum Pump

The Vacuum Pump is used to create a vacuum underneath the gel/Window Gasket
complex. The Vacuum Pump is connected directly to the Vacuum Regulator with vacuum
tubing. The Vacuum Pump is either 100–120 VAC or 220–240 VAC. The voltage is not
user settable and is configured at the factory. Verify that the voltage of the pump is
appropriate for your country.

2.8 Lid

The Vacuum Blotter Lid is made of a clear polycarbonate. The Lid shields the gel
from falling objects during transfer. It also protects the instrument during storage. The
Model 785 Vacuum Blotter Lid allows you to stack vacuum blotting units on top of each
other without damaging the units.

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