Thermo Scientific gibco CTS Rotea User Manual page 91

Chapter 4 Protocol Building Blocks
4
Concentrate Recovery
When product is being recovered from the chamber, a high density "slug" of cells is drawn out by the
pump. The OD Sensor detects this as a sudden drop in transmittance.
As the last of the concentrate is drawn from the chamber, the transmittance increases back to the value
determined at the start of the step.
The OD Sensor is used to calculate the volume of the concentrate and stores this as a volume in the
Volume Register for use as a Volume Trigger. When using it, set a percent of light transmittance
for the trigger to read as the start of concentrate, and a percent of light transmittance for the end of
concentrate. The step will advance when the OD Sensor detects the End of Concentrate % value
entered.
When using the OD Sensor Volume within a Harvest step, the volume Multiplier will be set at 1.0
meaning that the Harvest step will deliver the calculated OD Sensor volume.
To dilute the concentrate to a target ratio, a Normal Step can be added immediately after the Harvest
Step using a volume trigger and the OD Sensor volume from the Volume Register with a multiplier that
provides the appropriate dilution.
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CTS ™ Rotea ™ Counterflow Centrifugation System Process Design User Guide