Under which condition is a validation study required?

A validation study is particularly important whenever there is a change in reagent lot. This is because different lots of reagents can have variations in chemical composition, sensitivity, and specificity, which can significantly affect test results. Even slight differences in a reagent's formulation or performance can lead to inaccuracies and inconsistency in laboratory results. Therefore, validating the performance of a new reagent lot ensures that it consistently meets the required performance standards established during previous testing with the original lot.

By conducting a validation study in such cases, laboratories can confirm that the new reagent lot yields results that are comparable to those obtained with the previous lot. This process typically involves assessing parameters such as accuracy, precision, and any potential interference in the assay to ensure the reliability of laboratory results remains intact.

In contrast, while instrument recalibration, changes in source lamp or electrode, and changes in calibrator lot also warrant careful monitoring and may necessitate adjustments in testing procedures, these conditions do not typically require a full validation study in the same way that a change in reagent lot does. Validation is critical specifically for reagents due to their direct impact on the analytical performance of assays.