ThermoFisher Scientific HyPerforma DynaDrive - Cell Culture Operation Issues

I typically use level sensors to control the volume and feed rate or
supplement during a bioreactor run; how would I do this with the DynaDrive
S.U.B.?
Use load cells or a scale to control volumes based upon weight.
The DynaDrive S.U.B. is not equipped with level sensors. However, the S.U.B. can be set
up to allow supplement feeds and volumes to be managed by weight.
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Chapter 5 | Troubleshooting and frequently asked questions
5.2. Cell culture operation issues
Dissolved oxygen readings are low or slow to respond.
Check the physical condition of the dissolved oxygen (DO) probe, the
calibration of the probe, and gas flow rate into the DynaDrive S.U.B.
• DO probes require routine maintenance; replace the damaged probe or membrane
when necessary.
• Verify the DO probe calibration relative to setpoints of zero and span.
• Inspect the line sets connected to direct spargers for restriction (closed tubing
clamp, pinched line, low supply pressure).
Dissolved oxygen readings are erratic or unstable.
Adjust the bioreactor controller to suit the volume of your DynaDrive
S.U.B. system.
• Many dierent parameters can aect the ability of a bioreactor controller to maintain
a target setpoint during process control. Modern controllers utilize computer
algorithms to adjust targeted parameters; the most common technique is that of
a tunable controller that uses variables of the proportional integral derivative (PID).
Tuning these PID values to the specific characteristics of the system dynamics will,
in most cases, stabilize process parameters to an acceptable level. We recommend
that you consult the user guide of the particular bioreactor controller you are using.
• A grounding reference to the media can be created by using a grounding lead
between the tank and the body of the stainless steel DO probe or to the stainless
steel connector (if present) on the sample line of the BPC.
pH levels are questionable or out of range.
Verify the calibration of the probe and utilize either media or gas buffers.
• pH levels can be managed in a similar manner to conventional bioreactors once
calibration of the probe is verified by use of an o-line sample. Carbon dioxide gas
sparged through the media or headspace, biocarbonate levels in the media and
the addition of liquid titrant solutions all serve to manage the pH balance of the
bioreactor environment. See section 3.5.4 for more information on probe calibration
in the DynaDrive User’s Guide (DOC0090).
• A grounding reference to the media can be created by using a grounding lead
between the tank and the body of the stainless steel DO probe or to the stainless
steel connector (if present) on the sample line of the BPC.
Thermo Scientific 60DynaDrive S.U.B. Service Guide