Question 5 of 6 Advanced Scenario

When should QC methods be revalidated?

Short answer

Reassess method validity when a change or new evidence could affect its demonstrated fitness for purpose. The needed extent may range from targeted verification to substantial revalidation.

Why

A different column chemistry, software integration algorithm, critical reagent, sample matrix or site transfer can change sensitivity, specificity, precision or robustness. Start with documented change control and the method performance characteristics relevant to the new condition. If a validated method is transferred between laboratories, consider equipment differences, analyst training and sample handling as well as comparative performance data.

Choose an evidence package proportional to risk and explain why unchanged characteristics need no repeat testing. Track ongoing trends and investigate emerging method drift even without a formal procedure revision. Do not confuse a calibration check with full validation, and do not assume that every trivial document edit requires repeating the entire original study.

Common mistakes

Using an arbitrary fixed calendar interval as the sole trigger for revalidation

The interviewer might ask next

What would you reassess when replacing an HPLC detector with a different technology?