Pall Minimate Care And Use

Table of Contents

Introduction . . . . . . . . . . . . . . . . . . . . . . . .2

Applications . . . . . . . . . . . . . . . . . . . . . . .2

Product Information . . . . . . . . . . . . . . . . .2

Instructions For Use . . . . . . . . . . . . . . . . .3

Installation . . . . . . . . . . . . . . . . . . . . . . . .3

Calibrate Feed Pump . . . . . . . . . . . . . . . .4

Flushing . . . . . . . . . . . . . . . . . . . . . . . . . .4

Sanitization . . . . . . . . . . . . . . . . . . . . . . .5

(Recommended for critical applications)

Normalized Water Permeability (NWP) . . . .5

(Optional)

System Hold-up Volume (Optional) . . . . . .5

Integrity Test (Optional) . . . . . . . . . . . . . . .5

Buffer-Conditioning (Optional) . . . . . . . . . .5

Concentration/Diafiltration . . . . . . . . . . . . .6

Product Recovery . . . . . . . . . . . . . . . . . . .6

Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . .6

Storage of the Minimate TFF Capsules . . . .6

Disposal of the Minimate TFF Capsule . . . .6

Appendix A 7

Normalized Water Permeability . . . . . . . . .7

System Hold-up Volume . . . . . . . . . . . . .10

Minimate TFF Capsule Integrity Test . . . . .10

Flushing and Cleaning After Use . . . . . . .12

Appendix B 14

Specifications . . . . . . . . . . . . . . . . . . . . .14

Certification . . . . . . . . . . . . . . . . . . . . . .15

Ordering Information . . . . . . . . . . . . . . . .15

Support Literatures . . . . . . . . . . . . . . . . .15

Where to Find More Information . . . . . . .15

Care and Use Procedures PN 88227

Minimate™TFF Capsule

1

Introduction

The Minimate

™

tangential flow filtration (TFF) capsule is the
central part of a system for performing concentration or
diafiltration on solutions of biomolecules. It is available with
low protein binding Omega

™

ultrafiltration membranes in
several different molecular weight cutoffs. The membranes
are encased in a polypropylene housing with luer connectors
on the feed, retentate, and filtrate ports for easy connection
to a pump and accessories.

• For Laboratory and process development applications

• Ideal for evaluation, process development, process

optimization, and validation studies

• Scaleable to LV Centramate

™

and Centramate™systems

• Easily connected up to Minim

™

System or peristaltic

pumps

• Integrity tested and testable by user

• All plastic construction

Applications

Tangential flow filtration is a rapid and efficient method for
the concentration or diafiltration of biomolecules. It can be
used in a wide range of applications.

• Concentrate and desalt proteins, peptides, or nucleic

acids (DNA, RNA, oligonucleotides)

• Recover antibodies or recombinant proteins from clarified

cell culture media

• Process metal sensitive enzymes and molecules

• Separate (fractionate) large from small biomolecules

• Recover or remove viruses from solutions

• Prepare samples prior to column chromatography

• Concentrate samples after gel filtration

• Replace dialysis applications

• Depyrogenate water, buffers, and media solutions

Product Information

The Minimate TFF Capsule comes with threaded luer plugs
in each of the 4 ports. A fitting package with the following
components is included.

Fittings Package

Part No. 88216 includes:
A Tubing, 3.2 mm (1/8") i.d., 120cm (4 ft)
B Male luer-to-hose-barb fittings, 3.2 mm (1/8"), 2
C Female luer-to-hose-barb fittings, 3.2 mm (1/8"), 2
D Tubing clamps, 4
E Retentate screw clamp, 1
F Adhesive Strip (hook and loop), 1

Instructions For Use

NOTE: Read about the capsules operating limits in the
specification section of Appendix B of this manual.

Required Equipment

• Pump
A peristaltic pump or equivalent with variable speed

control capable of delivering a constant flow rate from 10
to 100 mL/min/capsule at pressures up to at least 2 bar
(30 psi). The peristaltic pump head should be sized to
accept 1.6 mm (1/16 in.) or 3.2 mm (1/8 in.) i.d. tubing.
The Minimate fitting kit includes 3.2 mm (1/8 in.) i.d. tubing.

• Feed reser voir
Appropriately sized for the volume of sample or flushing

solutions, e.g. 100 mL or 500 mL. Using a reservoir where
liquid is drawn from the bottom allows the sample to be
concentrated to a smaller volume due to the reduced
hold-up volume

Recommended Equipment

• Pressure measuring device
Pressure gauge or transducer and display. At least one is

recommended on the feed port. Additionally, one on both
the retentate and filtrate ports may be added.

• Magnetic stir plate and stir bar
Provide adequate mixing in the reservoir

B

A

E

D

F

C

2

• Stop watch
Measure elapsed time when determining flow rates

(crossflow and filtrate flux rate)

• Pipettes and sample tubes
Collect samples for analysis

• Beakers / reser voirs
To hold /collect sample, waste, etc.

• Graduated cylinders
For accurately determining collected volumes.

Installation

1. Remove the caps from the feed and retentate ports of

the Minimate TFF capsule.

Note: Do not discard caps. They are required for
storage.

2. Screw a male luer-to-hose-barb connector (included)

into each of the feed / retentate ports.

3. Cut a piece of tubing 3.2mm (1/8") i.d., long enough to

reach from the feed reservoir, through the pump head to
the capsule.

Note: Keep tubing lengths as short as possible to
reduce system hold-up volume.

4. Connect the tubing to the hose-barb on one of the feed

ports. Install the tubing in the pump head. Put the other
end of the tubing into the reservoir.

Note: If a pressure gauge or transducer is used,
connect the tubing to the pressure device. Then
connect the pressure device as close as possible
to the feed port using suitable connectors.

Note: Feed and retentate ports are interchangeable.
Depending on the orientation of the capsule, choose
the port that is at the lowest elevation as the feed
port. This allows for air to be easily expelled when
liquid is pumped through the capsule.

The recommended crossflow for the Minimate TFF
capsule is 30-40 mL/min.

5. Cut another piece of tubing, long enough to return from

the retentate port to the sample reservoir.

6. Attach the tubing to the retentate hose-barb and put the

other end in the reservoir. (Again, if a pressure gauge or
transducer is used, the tubing connects to the pressure
device, which must then be connected to the retentate
port.)

7. Place the retentate screw clamp on the retentate tubing

close to the retentate port (after the pressure gauge if
installed). Secure in place but do not tighten to restrict
the tubing.

8. Remove one of the filtrate caps.

9. Attach a female luer-to-hose-barb fitting to one of the

filtrate/vent ports.

Note: Depending on the orientation of the capsule,
choose the filtrate port that is at the highest elevation.
This allows air to be completely expelled from the
filtrate side of the membrane. The filtrate channel
can be drained easily by opening the other filtrate
port as a vent.

10.Attach a piece of tubing to the filtrate hose barb.

11.Install a tubing clamp over each piece of tubing where it
connects to the hose barb. Pinch the clamp to tighten.
Make sure the tubing is secure and does not easily pull
off the hose barb.

NOTE: Pall strongly recommends the use of pressure
gauges or transducers connected on both the feed
and retentate ports. If only one gauge is available, it
should be used on the feed port. The use of pressure
gauges allows accurate adjustment of feed pressures,
which provide for better reproducibility between
process runs. They can also help in the diagnosis of
system problems.

Figure 1

Typical Minimate

™

TFF Capsule set-up

The pump is connected with tubing between the process sample reservoir
and the feed port on the Minimate TFF capsule. Tubing connected to the
retentate port is returned to the reservoir. This allows flow of product across
(tangential to) the membrane surface to create a sweeping action that helps
prevent membrane fouling by reducing buildup of particles and product on
the surface. Pressure in this flow path, generated by the flow stream through
the channel and by restricting the tubing connected to the retentate port
with an adjustable clamp, is the driving force that creates liquid flow through
the membrane (filtrate flow rate). The average pressure applied to the
membrane is referred to as the transmembrane pressure (TMP). Increasing
the TMP increases the filtrate flow rate, up to a point. Applying too much
pressure will foul the membrane and reduce filtrate flow rate. Controlling the
TMP helps regulate the filtrate flow rate.

Tubing connected to one of the filtrate ports serves to carry the filtrate
(permeate) away from the device. The other filtrate port can be used as
a vent for draining all liquid in the tubing after the process is finished.

www.pall.com/lab

3

Calibrate Feed Pump

Note: If the pump does not have a digital read out of flow
rate, it may be useful to calibrate the pump. This makes it
easier to set flow rates.

Connect tubing to the pump and put both ends in a reservoir
with water. Prepare a pump curve by measuring flow rate at
different settings. Take measurements at 5 or more settings.
Record setting and flow rate. This will allow you to easily
adjust flow rates for the following procedures.

Table 1

Pump Calibration

Pump Setting Flow Rate

NOTE: Warnings are given in the following procedures
not to exceed a feed pressure of 2 bar (30 psi). This
warning is related to the pressure rating of the tubing.
If it is ascertained that the tubing being used can
withstand higher pressures and the tubing clamps
have been properly installed, higher pressures can be
used. It is strongly recommended that the system be
tested at the higher pressures with water before using
any potentially dangerous solutions, i.e. caustic
sanitizing agents. Do not exceed the pressure rating
of any component in the system.

Flushing

The Minimate TFF Capsule contains traces of glycerin
(humectant) and preservative (biocide). The humectant
insures that the membrane will easily accept water and allow
high flux, and the preservation combats microbial growth during
storage. These compounds should be flushed out before use.
More rigorous flushing and sanitization may be required for
more critical uses, while less flushing may be acceptable if
the intended use is less critical. If the Minimate TFF Capsule
has previously been used, cleaned and equilibrated in a
storage solution, the same preconditioning procedure may
be used. Follow these steps to flush out the storage solution.

STEP 1

Place the tubing from the suction side of your pump
(feed) into about 1 liter of 0.2 um-filtered deionized water
or water for injection (WFI). Place the tubing from the
retentate and filtrate ports into a drain or waste container.

STEP 2

Adjust pump to deliver a flow rate of about 40 mL/min.
Slowly tighten retentate screw clamp to increase
backpressure. This will increase flow through the filtrate
lines. Tighten clamp until filtrate flow rate is approximately
equal to the retentate flow rate or until feed pressure
reaches 2 bar (30 psi). Do not exceed a feed pressure of
2 bar (30 psi). Pump at least 250 mL of the water through
the retentate tubing and 250 mL through the filtrate tubing
to the drain (>500 mL total).

If the Minimate TFF capsule will not be sanitized prior to use,
it is recommended that this step is repeated to further remove
the glycerin and preservative.

STEP 3

When flushing is almost complete, open the vent port and
collect at least 10 mL of filtrate. A small beaker or test
tube can be used to collect the liquid. Replace the vent
cap when finished.

A three-port valve with luer connectors may be attached
to the drain port. A short piece of tubing attached to a
luer-to-hose-barb fitting can be connected to one of the
valve port. The valve can then be turned to drain the liquid
into the beaker or close off the port.

Sanitization (Recommended for critical applications)

If required, the Minimate TFF Capsule may be sanitized prior
to use. Sanitization is recommended whenever full compliance
with USP Biological Reactivity Test In Vitro <80> is req uired.
Refer to the MSDS for proper handling and safety
precautions when working with caustic solutions.

The following solutions can be used to sanitize and
depyrogenate the capsule.

1. 0.1 – 0.5N NaOH @ 35 – 45 °C

2. 0.1 – 0.5N NaOH + 200 ppm NaOCl @ 35 – 45 ºC

3. 200 – 400 ppm NaOCl (pH 6 – 8) @ 25 – 45 ºC
(Should not be used if any metal parts come in
contact with the solution.)

Sanitization is particularly important if the capsule has been
previously used, cleaned and stored.

STEP 1

Add about 200 mL of sanitizing solution into a reservoir.
Place feed tubing into reservoir. Place the tubing from the
retentate and filtrate ports into the reservoir.

STEP 2

Adjust pump to deliver about 50 mL/min. Slowly tighten
clamp on retentate tubing until filtrate flow rate is approx
mately 25% of the retentate flow rate. Do not exceed a
feed pressure of 2 bar (30 psi). If filtrate flow rate is already
>25% of retentate flow rate, proceed to next step.

4

STEP 3

Circulate the sanitizing solution for about 45 minutes
to 1 hour.

STEP 4

Flush out the sanitizing solution with water. Follow the
flushing procedure given above.

Normalized Water Permeability (NWP) (Optional)

This procedure is strongly recommended if the Minimate TFF
Capsule will be reused. The water permeability (filtrate flow
rate per unit of applied pressure) is a measure of performance
of the “original” clean membrane. The effectiveness of the
cleaning protocol, i.e. membrane recovery, can be evaluated
by comparing the NWP of the membrane after cleaning to
the “original” NWP.

NWP (after Cleaning)

Membrane recovery = ---------------------------------------------- X 100%

NWP (Original)

The procedures for determining NWP is given in Appendix A

System Hold-up Volume (Optional)

The System Hold-Up Volume is the total volume contained
within the feed/retentate flow path of the TFF system.
Most of this volume is recoverable. The Minimum Working
Volume is the system hold-up volume plus a minimum
volume of liquid that must remain in the bottom of the feed
reservoir at the operating flow rate in order to prevent air
from being drawn into the cassette system. Increasing the
cross flow rate, increases the volume of product required in
the bottom of the feed reservoir, in order to prevent air from
getting drawn into the pump. The minimum working volume
limits the maximum concentration factor achievable.
Knowing the minimum working volume, you can calculate
the minimum starting volume required to achieve a desired
concentration factor.

Minimum Minimum Concentration
Starting = Working x Factor
Volume Volume

If the actual starting volume is less than this value it will not
be possible to reach the concentration factor.

Reservoir design significantly affects the minimum volume
required to prevent air from getting into the system. The
Minim System 500mL reservoir was especially designed to
minimize the working volume in the system.

See Appendix A for a procedure to determine the minimum
working volume.

Integrity Test (Optional)

An integrity test is performed to identify any gross defects
in the device membrane or seals that could cause product
loss prior to use. Capsules are 100% integrity tested after
manufacturing. Therefore it is not necessary to perform an
integrity test on a new Minimate TFF Capsule. However,
for critical applications or if the capsule will be reused, it is
recommended that an integrity test be performed to confirm
integrity both before and after use.

Several procedures for performing an integrity test
(qualitative and quantitative) are given in Appendix A.

Buffer-Conditioning (Optional)

The buffer-conditioning step is used to precondition the
Minimate

™

TFF Capsule into the sample buffer (equilibrating
solution) before the sample is added. This adjusts the pH
and prevents the sample from being diluted with water, which
may lower the ionic strength and possibly cause precipitation
of product or other sample components. It is also used to
remove air bubbles from the system and equilibrate the
system components and fluid to operating temperature.

STEP 1

Add about 100mL of buffer solution into the reservoir.
Place feed tubing into reservoir. Place the tubing from the
retentate and filtrate port(s) into the reservoir.

STEP 2

Adjust pump to deliver about 50mL/min. Slowly tighten
clamp on retentate tubing until filtrate flow rate is
approximately 25% of the retentate flow rate. If filtrate flow
rate is already >25% of retentate flow rate, proceed to
next step. Do not exceed a feed pressure of 2 bar (30psi).

STEP 3

Circulate the buffer solution for 5-10 minutes.

STEP 4

Place the tubing from the retentate into a drain. Slowly
start the pump and run until the liquid in the reservoir just
reaches the bottom. DO NOT ALLOW AIR TO BE DRAWN
INTO THE TUBING.

Concentration/Diafiltration

Refer to the following application notes:

Introduction to Tangential Flow Filtration for Laboratory and
Process Development Applications, PN33213

Diafiltration: A Fast, Efficient Method for Desalting or Buffer
Exchange of Biological Samples, SD1599

A TFF Process Data Sheet is included at the end of
the Appendix B for use in recording experimental
conditions.

www.pall.com/lab

5

Product Recovery

Following the concentration/diafiltration process, the
product must be recovered from the system.

Product in Concentrate

After processing, a significant portion of the product is on
the membrane in the form of a “gel layer” and needs to be
recovered back into the solution before the system is drained.
Recirculating fresh buffer can recover most of this gel layer,
but may significantly dilute the product that you just
concentrated. The following procedure can improve recovery
without significant dilution. The actual procedure may have
to be varied depending on TFF system configuration.

STEP 1

Following concentration/diafiltration, open the retentate
valve and close off the filtrate line with a valve or screw
clamp. Adjust the pump to give a retentate flow rate of
40-50 mL/min. Circulate the product for 5-10 minutes.

STEP 2

Stop the pump. Put the retentate tubing into a collection
vessel. Start the pump and slowly pump out the product
into the collection vessel. Stop the pump just before the
volume in the reservoir reaches the bottom. Add to the
reservoir a volume of buffer equal to the system hold-up
volume. Pump out the product into the collection vessel
stopping just as the liquid level reaches the bottom of
reservoir. (This method displaces most remaining product
left in the cassettes and hardware.) Record the volume
collected.

STEP 3

Add just enough volume of buffer to the feed reservoir to
allow circulation without pulling in air. Circulate for 10
minutes to try and recover additional product. The
remaining liquid in the system can be pumped out into a
separate container by allowing air to be pumped through
capsule to displace it. A decision can then be made
whether to combine this volume with the main product.

Product in Filtrate

If the product is in the filtrate, raise the vent port so it is
higher than the collection vessel. Make sure the end of the
filtrate tubing is placed in the vessel. Open the vent port
and allow any remaining filtrate in the capsule and tubing
to be drained.

Cleaning

If the Minimate

™

TFF Capsule is to be reused, it must be
cleaned after use and properly stored. Recommended
cleaning solutions and protocols are given in Appendix A.

Storage of Minimate TFF Capsules

The objective for proper storage is to ensure the membranes
remain wet and to prevent microbial growth during the time
the membrane cassettes are not being used.

Recommended storage agents for Minimate TFF Capsules.

Storage Agents:

PERIOD SOLUTION

<3 days Sterile water or saline solution
<6 months 0.05N - 0.1N NaOH
>6 months 15% glycerin + 0.05% sodium azide

Recommended storage temperatures: 4°C - 15°C (optimal),
25°C (maximum). Do not freeze

Disposal of Minimate TFF Capsule

It is recommended that after use, and prior to disposal, the
Minimate TFF Capsule be flushed with clean water, sealed
into an autoclave bag, and autoclaved at either 121ºC for 30
minutes, or at 135ºC for 15 minutes to sterilize. Dispose of
the Minimate™ TFF Capsule in the bag, and do not open
after autoclaving.

DO NOT seal the inlet and outlet connectors of the
Minimate TFF Capsule prior to autoclaving as this
will cause a build up of pressure, which may rupture
the device.

6

Appendix A
Normalized Water Permeability

Determining the Normalized Water Permeability (NWP)
for the Minimate TFF Capsule

Water permeability is a function of the hydraulic resistance of
the membrane at a specified transmembrane pressure (TMP).
It is related to the pore size, pore depth, and number of pores
per unit area. It is significantly affected by temperature.
Water permeability can be used as a standard upon which
to measure the effectiveness of a cleaning regime after
sample processing.

The original NWP of the Minimate TFF capsule is
essential to calculate as it is used as the basis to
determine membrane recovery, i.e., how effectively
the membrane was cleaned.

This procedure should be performed with all new Minimate TFF
capsules after the flushing and sanitization steps have been
performed. The original NWP is determined by plotting the
water filtrate flux rates at several transmembrane pressures,
typically 0.3 - 1 bar (5 - 15 psig) for UF membranes. From
the graph, the original NWP is calculated at 0.7bar (10psi).
This value is chosen for ease of calculation.

Water quality should be “Water for Injection” (WFI) or at
minimum 0.2 µm filtered DI water. Calculated water
permeability rates are “normalized” to a temperature of
20 °C by using a temperature correction factor (TCF 20 °C)
given in Table 3, page 8.

For Minimate TFF capsules that are reused from this point
on, the NWP needs only be measured and determined at a
TMP of 0.7bar (10psi).

The NWP should be measured before processing and once
again after cleaning. An example for determining NWP is
shown below.

To determine the NWP, a pressure gauge is required
on the feed and retentate ports. Filtrate pressure
should be zero (0) provided there are no restrictions
on the filtrate line and that the filtrate line is open to
atmosphere.

Recirculate the filtrate and retentate streams back to the
feed reservoir to minimize the volume of water needed.

Removing air from the retentate

All air must be removed from the retentate channel before
determining the NWP as air bubbles will reduce the effective
filtration area, resulting in low NWP values.

Turn on and increase the pump speed to generate a reten­tate flow rate of 80-100mL/min. Stop and restart the pump
several times. Observe whether any air is expelled from the
retentate line when the pump is restarted. If no air is
observed, turn off the pump and proceed to the next step.

Determining the “original” normalized water
permeability.

1. Tighten the retentate clamp to completely restrict

retentate flow. The filtrate line should be open.

2. Adjust the feed flow rate to generate a TMP of

approximately 0.33 bar (5psi).

3. Measure the filtrate flow rate and calculate the flux rate

in LMH (liters/m2/h).

4. Adjust the feed flow rate to give a TMP of approximately

0.67 bar (10psi)

5. Measure the filtrate flow rate and calculate the flux rate

in LMH (liters/m2/h).

6. Adjust the feed flow rate to give a TMP of approximately

1.0 bar (15psi)

7. Measure the filtrate flow rate and calculate the flux rate

in LMH (liters/m2/h).

8. Plot Filtrate Flux Rate vs. TMP. Draw a straight line from

zero that best fits the data between 0.3 - 1 bar (5 to 15
psig). From the curve determine the water flux rate at

0.7 bar (10 psig)

The following table may be used as an example for
recording data and calculations.

www.pall.com/lab

7

Feed
Pressure

psi/bar

Retentate
Pressure

psi/bar

Filtrate
Pressure

psi/bar

TMP

psi/bar

Filtrate
Flow Rate

mL/min

Filtrate
Flux Rate

mL/min/cm

2

Filtrate
Flux Rate

LMH

Water Per­meability

LMH/TMP

NWP

LMH/TMP
@ 20°C)

Table 2.

Table for recording data and calculating NWP
Measurement Temperature: ________°C, TCF _______

TMP = ( P

feed

+ P

retentate

)/2– P

filtrate

(Assume P

filtrate

is “0” if no filtrate pressure gauge)

Filtrate Flux Rate (mL/min/cm

2

) = Filtrate Flow Rate (mL/min) / membrane area of 50 (cm2)

To convert mL/min/cm

2

to LMH

LMH = mL/min/cm

2

x [1liter/1000mL x 60min/h x 10,000cm2/1m2] = mL/min/cm2x 600

Filtrate Flux Rate (LMH) = Filtrate Flux Rate (mL/min/cm

2

) x 600

Water Permeability (LMH/TMP) = Filtrate Flux Rate (LMH) / TMP
NWP (LMH/TMP @ 20 °C) = Filtrate Flux Rate (LMH) x Temperature Correction Factor (TCF) at operating temperature

Table 3

Temperature Correction Factors (TCF 20°C) for determining Normalizing Water Permeability

Temperature Correction Factors (TCF 20°C) for determining Normalizing Water Permeability

T °C TCF 20 °C T °C TCF 20 °C T °C TCF 20 °C T °C TCF 20 °C

11 1.271 21 0.978 31 0.781 41 0.641
12 1.235 22 0.955 32 0.765 42 0.629
13 1.202 23 0.933 33 0.749 43 0.618
14 1.169 24 0.911 34 0.734 44 0.607
15 1.139 25 0.890 35 0.719 45 0.596
16 1.109 26 0.871 36 0.705 46 0.586
17 1.081 27 0.851 37 0.692 47 0.576
18 1.053 28 0.833 38 0.678 48 0.566
19 1.027 29 0.815 39 0.665 49 0.556
20 1.000 30 0.798 40 0.653 50 0.547

8

EXAMPLE
Determination of NWP on a Minimate TFF Capsule

Water filtrate flux rates were measured for a Minimate TFF
Capsule at TMP’s of 5, 10, and 15 psig. The temperature of
the water was 16°C. Determine the original normalized
water permeability (NWP).

Table 4

Data and Calculations from Example

Feed
Pressure

psi/bar
5
10
15

Retentate
Pressure

psi/bar
5
10
15

Filtrate
Pressure

psi/bar
0
0
0

TMP

psi/bar
5
10
15

Filtrate
Flow Rate

mL/min

4.6

9.2

13.8

Filtrate
Flux Rate

mL/min/cm

2

0.092

0.184

0.276

Filtrate Flux
Rate

LMH
55
110
165

Water
Permeability

LMH/TMP

11

NWP
LMH/TMP

@ 20°C)

12.2

Water Permeability =
110 LMH @ 10 psig = 11.0 LMH/psig

Normalized Water Permeability =

11.0 LMH/psig x TCF 20 °C where TCF 20 °C = 1.109
(Correcting water permeability for temperature;

from 16 °C to 20 °C)
Temperature correction factor from Table 3 for 16 °C =

1.109
Normalized Water Permeability =

11.0 x 1.109 = 12.2 LMH/psig

www.pall.com/lab

9

System Hold-up Volume

The system hold-up volume is the total volume contained
within the feed/retentate flow path of the TFF system. Most
of this volume is recoverable. The Minimum Working
Volume is the system hold-up volume plus a minimum
volume of liquid that must remain in the bottom of the feed
reservoir at the operating flow rate in order to prevent air
from being drawn into the cassette system. At a higher cross
flow rate, a greater volume of product is required in the bottom
of the feed reservoir, to prevent air from getting drawn into
the pump. The minimum working volume limits the maximum
concentration factor achievable. Knowing the minimum
working volume, you can calculate the minimum starting
volume required to achieve a desired concentration factor.

Minimum Minimum Concentration
Starting = Working x Factor
Volume Volume

If the actual starting volume is less than this value it will
not be possible to reach the concentration factor. Reservoir
design significantly affects the minimum volume required to
prevent air from getting into the system. The Minim System
500mL reservoir was especially designed to minimize the
working volume in the system.

Procedure to determine System Hold-up Volume

It is convenient to perform this procedure following the
determination of water permeability and before performing
air integrity measurements. The Minimate TFF capsule and
lines should already be filled with water and you will need
to drain the feed/retentate flow path for the air integrity test
anyway.

1. Clamp off the filtrate line.

2. Open the retentate screw clamp.

3. Pump down water in reservoir until volume is just above
bottom of reservoir; then stop pump. (Do not allow air to
be drawn into the tubing.)

4. Carefully transfer the retentate line into a 25mL graduated
cylinder. (On Minim System, turn retentate bypass valve
to drain and direct tubing into graduated cylinder.

5. Turn on pump and allow remaining liquid to be pumped
out.

6. Record the volume. This volume is the “system hold-up
volume”.

Procedure to determine Minimum Working Volume

1. Add water to the reservoir

2. Direct retentate and filtrate lines into feed reservoir.
Open the retentate clamp and close the filtrate clamp.

3. Adjust pump to deliver the operating retentate flow rate
that will be used for the process.

4. Direct the retentate line to drain. Watch the water in the
reservoir. When the water reaches a level where it
appears that air is just about to get pulled up into the
feed tubing, immediately return the retentate tubing back
into the feed reservoir. Continue to circulate the water for
a minute to confirm that no air is drawn into the tubing.
If any air is drawn in, add water back into the reservoir
until no more air is drawn into the tubing.

5. Direct the retentate tubing into a graduated cylinder and
allow all the liquid to be pumped out into the cylinder.

6. Stop the pump. If any liquid remains in the reservoir, add
it to the cylinder.

7. Record the volume in the cylinder. This is the minimum
working volume for the system.

Minimate TFF Capsule Integrity Test

Forward Flow Measurement is a quantitative test that
measures the rate of air diffusing through the wetted
membrane or passing through seal defects at a given
pressure. Air diffusion rates can be performed on cassettes
wetted with water or buffer solution.

Capsules are 100% integrity tested after manufacturing.
Therefore it is not necessary to perform an integrity test on a
new Minimate TFF Capsule. However, for critical applications
or if the capsule will be reused, it is recommended that a
forward flow air integrity test be performed to confirm
integrity before and after use.

The forward flow integrity test detects system or
membrane leaks. It does not provide a means to
determine retention characteristics of the membrane.

A simple, quick and inexpensive test protocol is described
below which can be performed without expensive measuring
equipment. The protocol is performed after the capsule has
been preconditioned and flushed with water in order to
completely wet-out the membrane. A pressure gauge at the
feed port is required. The pump must be self-priming, able
to pump air at pressures to 30psi. The Minim System and
most peristaltic pumps are suited for this procedure.

10

W

ATER DISPLACEMENT METHOD (QUANTITATIVE)

The first step is to thoroughly wet the membrane with water
assuring that each pore is filled with liquid. Once the membrane
is thoroughly wetted, the feed/retentate flow path is drained.
A graduated cylinder is filled with water and carefully turned
upside down in a beaker full of water. The end of the filtrate
tube is placed inside the graduated cylinder. The retentate
port is then closed off. The system is pressurized to about
10 psig (0.7 bar) through the device feed port. Air will
diffuse through the membrane, exiting through the filtrate
tubing and into the graduated cylinder. The amount of air
displaced over time is measured in mL/min. This is the air
diffusion (forward flow) integrity test value.

Initially water in the filtrate line will be displaced. Wait until air
starts to flow before taking any measurement, as any water
left in the feed channel will first pass across the membrane.
The membrane creates a barrier to air flow, not water flow.

Figure 2

Set-up for Air Integrity Testing of Minimate TFF Capsule

This protocol describes performing the procedure using a
peristaltic pump to generate airflow. For more accurate testing,
a regulated, compressed air or nitrogen supply should be used.

Forward Flow Air Integrity Test Procedure:

1. Empty the feed reservoir.

2. Open retentate and filtrate screw clamps and pump out
liquid from feed and retentate tubing.

3. Fill a 400 mL or larger beaker and a 25 mL graduated
cylinder with water.

4. Invert the full graduated cylinder into the large beaker.
(Place a piece of paper or Parafilm over the mouth of
the cylinder. Turn the cylinder over and remove the
piece of paper after the mouth of the cylinder is below
the water level in the beaker.) The cylinder should
remain filled with water.

5. Place the end of the filtrate tubing into the beaker.
The filtrate tube should be open.

6. Slowly turn up the pump speed to give a retentate flow
rate of 40 mL/min. Tighten the retentate screw clamp to
apply a feed pressure of 10 psi.

7. Watch for bubbles emerging at the end of the filtrate
tube. When the flow seems to be consistent, place the
end of the filtrate tubing into the inverted cylinder. The
cylinder can now rest on the bottom of the beaker.
Make sure that the filtrate tubing is not crimped under
the cylinder mouth.

8. Measure the amount of air entering the graduated
cylinder for sixty seconds (mL/min). Compare to integrity
specifications for the Minimate TFF capsule

9. If no air bubble reaches the cylinder within 3-5 minute,
the device is most likely within specifications. (Calculate
the volume in the filtrate tubing and compare to the
allowable airflow rate to see if sufficient waiting time has
been allowed.)

www.pall.com/lab

11

PRESSURE-HOLD TEST METHOD (QUALIT

ATIVE)

This procedure is a simple, quick method to test the
integrity of a capsule and system. It involves pressurizing the
capsule and then watching for a pressure decline. A drop in
pressure indicates air leakage. The method can be used to
check there are no leaks in connections and to confirm
there are no gross defects in the capsule membrane.

Forward Flow Air Integrity Test Procedure:

1. Empty feed reservoir.

2. Open retentate screw clamp and pump out liquid
from feed reservoir.

3. Clamp both the retentate and filtrate lines.

4. Slowly increase the pump speed to build up the
pressure to 1.6bar (25psi).

5. Stop the pump.

6. Clamp the feed tubing so air cannot flow backwards
through the pump head.

7. Slowly open the filtrate screw clamp to relieve the
pressure.

8. Observe the pressure on the feed pressure gauge.

After an initial drop when the filtrate clamp is opened, the
pressure should hold steady. (If pressure drops below 0.7
bar [10 psi] when the filtrate valve is opened, remove the
pump clamp and start the pump to bring the feed pressure
to about 0.7 bar [10 psi]. Stop pump and reapply clamp. If
the pressure holds for 2 minutes, the cassette integrity
shoud be good. On a defective cassette, the pressure
would drop the 10 psi in a few minutes.

9. Observe the filtrate line.

When the filtrate clamp is first opened, some liquid will be
displaced. This is liquid which remained on the feed side
and which is forced through the membrane. (Liquid will pass
freely through the membrane, but not the air.) Liquid on the
filtrate side will continue to be displaced if there is airflow
through the membrane or seals until all the liquid in the
tubing has been displaced. If you see a lot of air bubbling
through the filtrate line, there could be an integrity failure. In
this case a quantitative integrity test should be performed.

Flushing and Cleaning After Use

Recommended cleaning agents for Omega membranes
in the Minimate

™

TFF capsule.

Cleaning Solutions:

• 0.1- 0.5N NaOH at 35-45 °C

• 0.1- 0.5N NaOH + 200-400 ppm NaOCl at 35-45 °C

• 0.1N nitric, acetic or phosphoric acid

Post Treatment of Minimate TFF Capsule

Before introducing the cleaning solution into the membrane
system, remaining product and contaminants should first be
flushed free using either buffer or spent filtrate. The use of a
buffered flush will eliminate possible solubility changes.
Spent filtrate, assuming the product is in concentrate,
eliminates the need for fresh buffer or water to be used to
flush the system prior to introducing the cleaning agent,
eliminating additional fouling concerns.

To flush the system, the retentate is directed to drain. For
cleaning, the retentate and filtrate lines are returned back to
the feed reservoir.

To assure proper flushing, it is essential to obtain high fluid
velocities through the system to create sufficient turbulence
at all wetted surfaces (membrane, tubing, components, etc.).
It is also important to develop a positive pressure profile
along the entire membrane path length (feed to retentate).
The procedure below will accomplish both requirements.

Note: This procedure requires a screw clamp on both the
retentate and filtrate lines.

Flushing the retentate stream of excess matter

1. Direct the filtrate and retentate streams to waste.

2. Add buffer or spent filtrate to feed reservoir.

3. Open the retentate screw clamp and close the filtrate
screw clamp.

4. Start the pump and increase speed until retentate flow
rate is 50-80 mL./min.

5. Flush about 200mL to drain to assure that a thorough
flushing is accomplished.

Flushing the system with water

1. Drain the system

2. Add at least 500 mL of 0.2 um-filtered deionized water
or WFI. Place the tubing from the retentate and filtrate
port into a drain or waste container.

3. Adjust pump to deliver a flow rate of about 40mL/min.
Slowly tighten the retentate screw clamp until the filtrate
flow rate is approximately equal to the retentate flow rate.
Do not exceed a feed pressure of 2 bar (30 psi).

4. Pump at least 250 mL of the water through the retentate
tubing and 50 mL through the filtrate tubing to the drain
(>500mL total).

Adding and circulating cleaning agent.

1. Drain system. Add the cleaning solution to the feed reservoir.

Note: Cleaning is more effective if solution is warmed
to 35-45°C before adding to reservoir.

12

1. Return the retentate and filtrate line back to the feed reservoir

2. Open the retentate and filtrate screw clamps.

3. Increase the pump speed to deliver 50-80 mL/min
through retentate.

4. Adjust retentate clamp to generate a retentate pressure
of about 2 bar (30 psi).

5. Run for about 2-3 minutes to flood the membrane with
cleaning solution

6. Open the retentate clamp and close the filtrate clamp.

7. Adjust pump speed give a retentate flow rate of 50-80
mL/min

8. Run for 45 - 60 minutes for cleaning.

Note: If the cleaning solution gets “dirty” after only a
few minutes, flush it out from the system using the
following procedure and then immediately add fresh
cleaning solution and repeat the cleaning cycle. Do
not continue to circulate dirty cleaning solution as it
will reduce the effectiveness of the cleaning process.

Flushing the Cleaning Agent from capsule

1. Direct retentate and filtrate lines to drain.

2. Open retentate and filtrate clamps.

3. Remove feed tubing from cleaning solution.

4. Start pump and run until all solution has been purged
from capsule.

5. Drain reservoir and add water for flushing, 0.2 um filtered
deionized water or WFI.

6. Close the filtrate clamp.

7. Turn on the pump and adjust to 50-80 mL/min. Run at
least 250mL through retentate to drain.

8. Stop the pump. Open filtrate clamp and then close
retentate clamp. Refill reservoir with water if necessary.

9. Start pump and increase flow until the feed pressure is
about 2 bar (30 psi). Run until a minimum of 250 mL is
flushed through the filtrate to drain.

Determining the Membrane Recovery for the cleaned
Minimate

™

TFF Capsule

Membrane recovery is a calculation that defines the efficiency
of the cleaning process performed on the membrane capsule.

It compares the normalized water permeability (NWP) after
cleaning to the "original" NWP. The original NWP was meas­ured when the membrane was first installed and precondi­tioned (described on page 5)

Water should be wateWFI or at a minimum, 0.2 µm filtered
DI water.

All water permeability rates are normalized to a temperature
of 20 °C by using a temperature correction factor (TCF 20 °C)
in Table 3.

Determining the water permeability after cleaning

1. Add water to the reservoir.

2. Return the retentate and filtrate line back to the feed
reservoir

3. Open the retentate and filtrate screw clamps.

4. Increase the pump speed to deliver 80 -100 mL/min
through retentate. Stop and restart the pump several
times. Observe whether any air is expelled from the
retentate line when the pump is restarted. If no air is
observed, turn off pump and proceed to the next step.

5. Close the retentate clamp. Adjust the pump flow rate to
develop an transmembrane pressure of approximately
10 psig (0.7 bar).

TMP = ( P

feed

+ P

retentate

)/2– P

filtrate

6. Measure the filtrate flow rate

7. Calculate the filtrate flux rate in mL/min/cm2 and LMH.

8. Calculate the water permeability at the recorded
transmembrane pressure.

Water Permeability = Filtrate Flux Rate (LMH)/TMP

9. Calculate the Normalized Water Permeability using the
temperature correction factor (TCF 20°C) in Table 3,
page 8.

NWP = Water Permeability x TCF

20°C

10.Calculate the membrane recovery.
Membrane Recovery = (NWP after cleaning /“original”

NWP) x 100%

If the membrane recovery is less than 75 - 80%, perform
another cleaning cycle starting from the step, “Adding and
circulating cleaning agent”.

If after the second cleaning the NWP has increased but
acceptable recovery has not been achieved, perform
another cleaning cycle. If after the second cleaning the NWP
has not increased, the cleaning agent or parameters (time,
temperature, etc.) may have to be altered.

NOTE: Between uses, the capsule is stored in a
caustic solution (typically 0.05N - 0.1 NaOH).

During this time, remaining foulants on the membrane
may be released and removed from the capsule when
it is flushed prior to the next use. Therefore, it is not
unusual to find membrane recoveries increase after
storage versus values obtained immediately after
cleaning.

www.pall.com/lab

13

Appendix B
Specifications

Materials of Construction

Filter media: Omega membrane (m-polyethersulfone)

Housing: polypropylene, glass reinforced

Screens, housing, housing sealing ring, fittings polypropylene
Membrane plate/filtrate channels polyethylene
Internal gasket ethylene propylene elastomer

Product Dimensions 20cm x 3.8cm x 1.8cm

(L x W x H, nominal) 8in x 1.5 in x 0.7 in

Effective Filtration Area 50 cm

2

Product Hold Up Volume (feed/retentate) ~1.6mL

Forward Flow Air Integrity Value ≤ 7 mL/min at 0.75 bar (10 psi)

Operating Temperature Range 5 ºC (41 ºF) to 50 ºC (122 ºF)

Maximum Operating Pressure at 20 ºC (68 ºF): 4 bar (400 kPa, 60 psi)

Recommended Crossflow 30-40 mL/min (0.6-0.8 Liters/min/ft

2

)

Connections

Feed Female Luer with external thread
Retentate Female Luer with external thread
Filtrate Male luer with threaded lock ring

14

Certification

Pall Corporation certifies that the Minimate

™

TFF Capsule is:

• 100% POST PRODUCTION INTEGRITY TESTED

• Field integrity testable using pressure hold or forward
flow tests

• Materials of construction pass United States
Pharmacopeia (USP) Biological Reactivity Test,
In Vivo <88> after preconditioning

• In compliance with published product specifications

• Manufactured in ISO9000 certified facilities

The certificate of test provided does not apply to products
that have been opened or damaged by conditions outside
the control of Pall Corporation.

Where to Find More Information

This manual, Minimate TFF Capsule Care and Use
Procedures (PN88227) is supplied on the Minimate TFF

Capsule CD-Rom (PN88201) enclosed with the product.
Many additional accessories are available for this product,
including pumps, reservoirs and connectors. For further
assistance, please consult with your local Pall representative
or distributor.

Support Literature

• Minimate TFF Capsule Data Sheet, USD 2218

• Minimate TFF Capsule Quick Start Guide, PN 88200

• Minimate TFF Capsule CD-Rom, PN 88201

• Introduction to TFF for Laboratory and Process
Development Applications, PN 33213

• Diafiltration: A Fast, Efficient Method for Desalting, or
Buffer Exchange of Biological Samples, PN 33289

• Desalting and buffer exchange by Dialysis, Gel Filtration
or Diafiltration PN 33290

• Minim

™

System Product Data, USD 2069

• LV Centramate

™

Data Sheet, USD 2098

• Centramate

™

Cassette Data Sheet, USD 2080

www.pall.com/lab

15

16

Pall Life Sciences

Tangential Flow Filtration Process Data Sheet

Sample Identification: TFF System: Date:

Membrane/Cassettes:

Application: Membrane Area: Operator:

Process Feed

Pressure Readings Flow Rate/Flux Rate Volume

Conc. Diafiltrate

Comments

Time Temp Feed Retent. Filtrate TMP Delta P Retent. CFF Filtrate Filtrate Feed Filtrate Factor Volumes

hr:min °C psi/bar psi/bar psi/bar psi/bar psi/bar L/min L/min/ft

2

mL/min LMH mL mL x DV

Initial Water Data

Filtrate Flux Rate

Delta P

Process Data Optimization: Yes or No

Final Water Data

Filtrate Flux Rate

Delta P

COLUMN UNITS DESCRIPTION

Process Time hr:min Elapsed process time from beginning of concentration or diafiltration process.

Either record actual clock time or elapsed time.

Feed Temperature °C Measured temperature of process solution

Pressure Readings

Feed psi/bar Feed Pressure (PF)
Retentate psi/bar Retentate Pressure (PR)
Filtrate psi/bar Filtrate Pressure (PP)
Transmembrane Pressure (TMP) psi/bar [(PF + PR) ÷ 2] - PP
Delta P psi/bar Pressure differential (PF – PR)

Flow Rate / Flux Rate

Retentate Flow Rate L/min Measured retentate flow rate
Cross Flow Flux (CFF) L/min/ft

2

Retentate flow Rate ÷ membrane area (Liters / minute / ft2)
Filtrate Flow Rate mL/min Measured filtrate flow rate
Filtrate Flux Rate LMH Filtrate flow rate ÷ membrane area (Liters / hour / meter

2

)

Volume

Feed mL Remaining Feed Volume = (Starting Volume) – (Total collected filtrate volume)

(Starting Volume equals process volume added to reservoir plus hold-up

volume if system was filled with liquid.)
Filtrate mL Total collected filtrate volume
Concentration Factor X Starting Volume ÷ (Starting Volume – Filtrate Volume)
Diafiltration Volumes DV The number of DV’s of diafiltration solution added.

1 DV = Remaining Feed Volume at start of diafiltration.
Comments Indicate any observations or information considered important to fully

describe process or events.

To convert milliliters /minute to liters/ hour, multiply by 0.06
To convert square feet to square meters, multiply by 0.093

TFF Process Data Sheet Column Description

www.pall.com/lab

17

© 2003, Pall Corporation. Pall, , Omega, and Minimate are trademarks of Pall Corporation. ® indicates a trademark
registered in the USA. is a service mark of Pall Corporation. All rights reserved.
*PharMed Masterflex is a registered trademark 6485 of Norton who makes tubing, DuPont makes material.

4/03, Xk, GN03.0678 PN88227

Pall LIfe Sciences

600 South Wagner Road
Ann Arbor, MI 48103-9019 USA

800.521.1520 toll free in USA

734.665.0651 phone

734.913.6114 fax

Pall Corporation

2200 Northern Boulevard
East Hills, NY 11548 USA

800.717.7255 toll free in USA

516.454.4500 phone

516.625.3610 fax

Visit us on the Web at www.pall.com/lab
E-mail us at [e-mail]

Australia – Lane Cove, NSW

Tel: [phone]
1800 635-082 (in Australia)
Fax: [phone]
Austria – Wien
Tel: [phone]
Fax: [phone]
Canada – Ontario
Tel: [phone]
800-263-5910 (in Canada)
Fax: [phone]
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Tel: [phone]
800-435-6268 (in Canada)
Fax: [phone]
800-808-6268 (in Canada)
China – P. R., Beijing
Tel: [phone]
Fax: [phone]
France – St. Germain-en-Laye
Tel: [phone]
Fax: [phone]
[e-mail]

Germany – Dreieich
Tel: [phone]
Fax: [phone]
[e-mail]
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Tel: [phone]
Fax: [phone]
Italy – Milano
Tel: [phone]
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or 02-41-22-985
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Tel: [phone]
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[e-mail]

18

Product No. Description

OAD65C12 Minimate TFF Capsule w/650 dalton Omega

™

OA001C12 Minimate TFF Capsule w/1Kd Omega
OA003C12 Minimate TFF Capsule w/3Kd Omega
OA005C12 Minimate TFF Capsule w/5Kd Omega
OA010C12 Minimate TFF Capsule w/10Kd Omega
OA030C12 Minimate TFF Capsule w/30Kd Omega
OA050C12 Minimate TFF Capsule w/50Kd Omega
OA070C12 Minimate TFF Capsule w/70Kd Omega

Ordering Information

Minimate TFF capsules; Self contained Ultrafiltration Tangential Flow Filtration capsule with Luer Connectors

Product No. Description

OA100C12 Minimate TFF Capsule w/ 100Kd Omega
OA300C12 Minimate TFF Capsule w/ 300Kd Omega
OA500C12 Minimate TFF Capsule w/ 500Kd Omega
OA990C12 Minimate TFF Capsule w/ 1000Kd Omega

88216 Minimate Fittings kit, Contains: Male luer to

3.2 mm (1/8") hose barb, Female luer to

3.2 mm(1/8") hose barb, 3.2 mm (1/8") i.d.
tubing, Tubing screw clamp, Tubing clamps,
Adhesive strips (loop and hook)

Product No. Description

FS700X06 3-port valves (6)
FS700M01 MINIM™ System Pump station with 500mL

reservoir, 1.6mm (1/16 in.) i.d. tubing,

3.2 mm (1/8 in.) i.d. tubing, 3 port valves,
fittings. Multi-voltage unit. Supplied with
detachable power cord.

FS720M01A Pressure Display Unit*

Display reading in psi,100-120VAC, 60 Hz

FS720M01B Pressure Display Unit*

Display reading in bar,200-240VAC, 50 Hz

*Three digital displays for Feed, Retentate and Filtrate
Pressure (includes 6 pressure transducers).

Complementary Products

Product No. Description

FS700X14 Pressure Transducer (1), Sterile Packed (for

use with PN FS720M01A and FS720M01B)

FS700X15 Pressure Transducers (12)

Individually Sterile Packed (for use with
PN FS720M01A and FS720M01B)

FS710M01 Pressure Gauge Assembly (1), (two or three

recommended: feed, retentate, and filtrate)

FS007X75 500 mL Ultrareservoir, includes pressure

gauge, fittings and three-way valve