We are sharing to you a sample PCR Control Performance Monitoring sheet which you can download and edit as you see fit.
Prior to monitoring your PCR kit’s performance per run:
As part of good lab practice, a lab should perform a QC check (parallel-run the new batch/lot of PCR kits vs a previously-verified batch) prior to routine use in patient testing. If the new batch yields equivalent results as with the previously-verified PCR kit batch/lot, this can now be considered as QC-passed and can be used in routine patient testing.
Why do we need to record and monitor the performance trend of our PCR kit positive & negative controls?
A lab should expect for its PCR kit controls to fall within a certain lab-defined acceptable range. For example, for RITM, we define ‘acceptable range’ as 3.2 Ct values up (corresponds to a 10-fold decrease in concentration that we interpret as degradation) and 1 Ct value down (possibly due to pipetting variation) from the mean Ct value established for the PCR kit’s control during the QC check step.
Trend monitoring provides evidence of sustained reagent viability for testing. A consistent trend (for RITM, we qualify this as 3 consecutive runs) of PCR kit control falling beyond the acceptable range warrants further action (investigation, incident reporting, disposal, etc).