Cellicon
TM
Perfusion Solution for Process Development User Guide
19
Flow
setpoint
User inputs a desired flow rate
and system will maintain that
flow rate by adjusting pump RPM.
Speed
setpoint
User inputs a desired speed in
RPM and is held constant, but
actual flow rate may fluctuate.
For this reason, the speed
setpoint is recommended only
when priming the system.
In flow setpoint mode the user can define the
desired crossflow rate. The bench scale filter is
recommended to run at a crossflow of 100 mlpm.
Select
START PUMP
to begin and leave the
pump on for the duration of the run.
Starting Perfusion
Once the cell retention device and system
have been attached and primed, cells can be
added to the bioreactor. Typically there is a
delay between the inoculation and the start
of perfusion. The recirculation pump can
remain on during this time.
Before starting perfusion, a closed and sterile
perfusate (permeate) line must be welded to
a collection vessel (bag or bottle) to collect
the spent media. Attach a peristaltic pump
(not included with the cell retention system)
to the perfusate (permeate) tubing line to
pull spent media out of the cell retention
device. Continuously run the perfusate
(permeate) pump at a flow rate of 23 LMH
or less. If the flow rate of the perfusate
(permeate) pump is greater than 23 LMH it
might prematurely foul the filter. The flow
rates chosen (VVDs – vessel volumes per
day) are specific to each process.
Run Maintenance
Data Logging
Insert a USB flash drive into the USB port
in the back of the controller. The controller
can record process data while a run is in
progress. Data logging can be initiated by
selecting the toggle on the bottom, right-
hand corner of the main menu screen to
On
.
Select the toggle again to switch back to
Off
and stop data logging. Removed the USB
drive from the controller.
To adjust data logging settings, select
Settings
System
Data Logging. Choose
the name of the file saved on the USB drive,
the log interval, and the log file size. Choose
a log interval of 60 seconds or greater and a
log file size of 65000 lines.
Insert the USB drive into a computer to view
data. Open Microsoft Excel and click the
Data
tab on top, then download data
From Text/
CSV
. Choose the correct file from the flash
drive and follow prompts to open data in a
new sheet.
Sampling the
Perfusate (Permeate)
A sampling container should be used to take
samples from the perfusate (permeate) of
the device. The sampling container should
be placed between the perfusate (permeate)
pump and the perfusate (permeate)
collection bag.
Follow this procedure to take a sample:
1. Locate sample collection vessel.
2. Briefly stop perfusate (permeate) pump,
clamp line to collection vessel (Clamp 2) and
unclamp line to sampling container (Clamp 1).
3. Start the perfusate (permeate) pump
and fill sampling container until the
appropriate volume is collected.
4. Stop the perfusate (permeate) pump,
clamp sampling line (Clamp 1), unclamp
collection vessel line (Clamp 2).
5. Restart perfusate (permeate) pump.
6. Use a syringe to collect sample from
sampling container.
Changing the Filter
The Cellicon
T
M
Perfusion filter has been
designed to have a high throughput to
support N-1 perfusion applications. The
pressure profile of the pressure sensors and
the recorded TMP can describe fouling of
the membrane. If fouling occurs it will cause
the perfusate (permeate) pressure (P3) to
become negative, and will increase the TMP
reading (TMP = [(P1 + P2) / 2 ] – P3). Stop
the run when TMP > 5 psi.
If the run is not complete when TMP = 5
psi, replace the old filter with a new filter
and continue the run. Follow these steps to
replace the filter:
1. Pause the perfusate (permeate) pump.
2. Turn off the recirculation pump by
selecting
STOP PUMP
on the main menu.
3. Use a tube sealer to seal the lines
connecting to the old filter. Three
seals are needed on: the feed line,
the retentate line, and the perfusate
(permeate) line. Ensure there is enough
space on the bioreactor side to complete
another weld when the new device is
added.
4. Cut through the middle of all three tube
seals to disconnect the old filter.
