XCell™ Lab Controller
User Guide
15 repligen.com XC-LAB-UG-V4
The flow rate of cell culture liquid from A2B does not remain constant over the course of a pump
stroke. As the diaphragm begins to move from a stationary position, the flow rate starts relatively
low. As the diaphragm travels further, the flow begins to increase and reaches a maximum value
approximately at the midpoint. Toward the end of the diaphragm trajectory, the flow rate once
again begins to slow. The change in the flow rate over the course of the pump stroke may therefore
be considered to be sinusoidal. The controller records the
instantaneous flow rate
approximately
every ~100 ms during each stroke (ml/min) and then averages all stroke measurements over the
cycle to generate the
ATF flow rate
. The ATF flow rate contains data averaged over 10 cycles, which
largely eliminates outliers and noise.
You control the ATF flow rate by entering a value for the
ATF Flow Rate Set Point
. Due to the
sinusoidal nature of the flow rate over the course of an ATF cycle, the measured instantaneous flow
rate may be either higher or lower than the reported ATF flow rate over the course of each stroke.
Generally, you do not need to consider the Instantaneous Flow Rate, except during troubleshooting.
A well-controlled XCell ATF® Device will have the following flow rate properties:
•
achieves maximum flow quickly
•
switches smoothly between strokes
•
minimal to no delay between strokes (referred to as the
Dwell Time
)
•
maximum liquid displacement during strokes (referred to as
Displacement Volume
)
The recommended ATF Flow Rate Set Points and the typical Displacement Volumes are programmed
into the ATF System as default values. The calculated average displacement volume from the flow
sensor is updated every 30 minutes to further improve the response accuracy.
6.4
System configurations
Figure 4. Configuration - bioreactor, controller, and utilities
The XCell ATF® Lab System is designed to support multiple controllers simultaneously. Each
controller, in turn, supports multiple devices and bioreactors (
). The multiplicity from your
utilities to your bioreactors provides significant facility and configuration flexibility.
Both positive air pressure and the vacuum source lines connect to intermediate manifolds with one
input and four outputs. Volumetric air flow and vacuum requirements will vary with the number of
controllers as well as the number and the model of filtration devices used.
