Normal pH profile
Figure 1: Flat pH, Unchanging and Steady for 7 Days
Ideal pH Profile
Equilibration Profile
Figure 2: Initial pH Decrease in First 24 Hours
Solution: Allow an overnight or longer equilibration time before starting pH test
Sawtooth Profile
Figure 3: Daily pH Spikes That Return to Steady State
Solution: Modify door openings, daily lab functions or HVAC schedules that may cause pH fluctuations
pH Drift Profile
Figure 4: pH Slowly Increases or Decreases During 7-Day Testing
Solution: Download data file and send to support@safesens.com
A change to the drift correction value is needed for the specific media used in the lab
Solution: Download data file and send to support@safesens.com,.
Continuous Decrease Profile
Figure 5: pH Decreases Continuously - 1 Minute Testing
Solution: Update TrakPod® firmware and adjust drift correction terms for 1 minute testing frequency
Incubator Off Profile
Figure 6: Incubator Turned Off (Ex: Cleaning)
Characterized by a pH spike upwards followed by decrease in pH
Solution: Do not monitor pH while incubator is not in use for cell culturing
Evaporation Profile
Figure 7: Steady pH Rise From Evaporation
Check if any media is still present in sensor at end of 7 days
Solution: Ensure sufficient oil volume and density is used when preparing sensors
pH Overshoot Profile
Figure 8: Moderate pH Increase From Overshoot
Solution: Check incubator function and CO2 levels with external meter at various points in time
Common in big box incubators. Cause is related to the incubator adding too much Carbon Dioxide
Temperature Profile
Figure 9: pH Fluctuations From Incubator Temperature Changes
Solution: Check and modify incubator temperature over time to meet cell culture QC standards
Humidity Profile
Figure 10: Effects of Humidity on pH
pH spikes up then stabilizes (3 hour removal) or constantly increases (Long removal)
Solution: Be consistent about incubator humidity- this impacts incubator CO2 readings
LED On Profile
Figure 11: LED Light is Constantly On
Initially correct pH followed by pH drop over 7 days - 30 minute testing
Solution: Check incubator function and TrakPod LED. If LED is always on, Contact support@safesens.com
Bacteria Profile
Figure 12: Bacteria-Spiked Media
Solution: Disinfect incubator and check stock media for contamination
