When QC values slowly drift up or down over time, this sometimes indicates that a recalibration is necessary. Recalibration "resets" the relationship between analyte concentration and signal, which may bring subsequent QC analysis back to the expected relationship. Sometimes, QC drifts are an expectation of the clinical assay, and recalibration must occur at regular intervals to maintain analytically appropriate QC and patient results.
Recalibration is also a helpful second-tier troubleshooting tool, even when an evident QC drift is not apparent. Recalibration is best completed with new, unopened calibrator material or entirely new calibrator lots. Sometimes multiple sets of calibrator material must be analyzed and reviewed to determine the root causes of failures.
