Many times the instrument and current calibration are within normal analytical parameters. However, the last QC that was used was compromised in some way. This could be due to:
- Degradation due to the age of the QC material
- Even if QC has not expired based on claims from the manufacturer, QC can still degrade to an unacceptable degree.
- Degradation due to incorrect storage conditions
- An example would be QC material left on the bench at room temperature all night when refrigeration was required.
- Incorrect QC material was used altogether
- A new lot of QC material that has different expected ranges that were not accounted for
- Sometimes, new QC lots just behave differently, even if ranges are claimed to be identical.
Repeat analysis with fresh QC material can help determine whether the failures are QC-related or if further troubleshooting needs to occur.
Repeat QC analysis is best completed with new, unopened QC material or entirely new QC lots. Sometimes multiple sets of material must be analyzed and reviewed to determine the root causes of failures.
