l
Observe pressure measurements before and after first module
(3 μm) (see Note 11).
l
Clean the system by sterilization, either in the autoclave, or by
liquids, as described for the regeneration of the Sartocon
® Slice
200 cassette (Fig. 1).
3.3.3 Purification
All buffers must be sterile, and filtered at 0.2 μm.
l
Place the system in a sterile clean bench.
l
Install the Sartocon
® Slice 200 cassette in the Sartocon
® Slice
200 Holder as described by the manufacturer and, next, in the
benchtop filtration system with a torque of 25 Nm. Flush the
system with 10 L of water per 0.1 m
2 filter area before initial use
(see Note 10). Afterward, perform an integrity test and determine the clean water flux as described in the manual.
l
To prepare the membrane for the filtration runs, several washing
steps in TRM are necessary (see Fig. 2a). The flow rate should be
the same as in the following purification process. First, flush the
membrane with 400 mL of sterilized and filtered water in TRM
for 30 min. Secondly, sterilize the membrane with 400 mL of
1 M NaOH in TRM for 30 min. Thirdly, flush the membrane
again with 400 mL of water in TRM for 10 min. Fourth, flush
the membrane with 400 mL of PBS, or other physiological
saline, in TRM for 10 min. Before starting the experiments, a
sterility test should be done.
l
Prepare the sample from the clarification step for filtration by
measuring the volume. In the experiments conducted, up to
500 mL were used.
l
Start filtration with a constant flow of 150 mL/min (see Note
12). Operate the system in the recycling mode for 5 min to
equilibrate the membrane, followed by the filtration cross-flow
mode (seeFig. 2b) until the entire sample has been filtered and
no air is drawn into the system anymore.
l
Take samples (500 μL) throughout the filtration run, e.g., after
every 150 g of additional permeate weight, from the permeate
and the retentate as well as from an initial feed sample.
l
Monitor the differential pressure of filtration module (see Note
13).
l
After filtration, clean the system, as described in the Subheading
3.3.4 of Sartocon
® Slice 200 cassettes (Fig. 2).
3.3.4 Regeneration
of Sartocon
® Slice 200
l
Use a flow rate of 500 mL/min. Flush cassette with 300 mL of
water in TRM for 5 min in the cross-flow mode as well as backflush. Flush cassette with 400 mL of 1 M NaOH, heated to
378
Friederike Eilts et al.
Observe pressure measurements before and after first module
(3 μm) (see Note 11).
l
Clean the system by sterilization, either in the autoclave, or by
liquids, as described for the regeneration of the Sartocon
® Slice
200 cassette (Fig. 1).
3.3.3 Purification
All buffers must be sterile, and filtered at 0.2 μm.
l
Place the system in a sterile clean bench.
l
Install the Sartocon
® Slice 200 cassette in the Sartocon
® Slice
200 Holder as described by the manufacturer and, next, in the
benchtop filtration system with a torque of 25 Nm. Flush the
system with 10 L of water per 0.1 m
2 filter area before initial use
(see Note 10). Afterward, perform an integrity test and determine the clean water flux as described in the manual.
l
To prepare the membrane for the filtration runs, several washing
steps in TRM are necessary (see Fig. 2a). The flow rate should be
the same as in the following purification process. First, flush the
membrane with 400 mL of sterilized and filtered water in TRM
for 30 min. Secondly, sterilize the membrane with 400 mL of
1 M NaOH in TRM for 30 min. Thirdly, flush the membrane
again with 400 mL of water in TRM for 10 min. Fourth, flush
the membrane with 400 mL of PBS, or other physiological
saline, in TRM for 10 min. Before starting the experiments, a
sterility test should be done.
l
Prepare the sample from the clarification step for filtration by
measuring the volume. In the experiments conducted, up to
500 mL were used.
l
Start filtration with a constant flow of 150 mL/min (see Note
12). Operate the system in the recycling mode for 5 min to
equilibrate the membrane, followed by the filtration cross-flow
mode (seeFig. 2b) until the entire sample has been filtered and
no air is drawn into the system anymore.
l
Take samples (500 μL) throughout the filtration run, e.g., after
every 150 g of additional permeate weight, from the permeate
and the retentate as well as from an initial feed sample.
l
Monitor the differential pressure of filtration module (see Note
13).
l
After filtration, clean the system, as described in the Subheading
3.3.4 of Sartocon
® Slice 200 cassettes (Fig. 2).
3.3.4 Regeneration
of Sartocon
® Slice 200
l
Use a flow rate of 500 mL/min. Flush cassette with 300 mL of
water in TRM for 5 min in the cross-flow mode as well as backflush. Flush cassette with 400 mL of 1 M NaOH, heated to
378
Friederike Eilts et al.