AOAC Guidance on FA Immunoassay Validation (November 2023)

Protein extracƟon at two different days with two different operators and one ELISA means that one extract has to be stored. The influence of the storage Ɵme and temperature could be greater than the operator influence (depending on the test matrix). Therefore, some kit manufacturers require the ELISA to be carried out immediately aŌer the extracƟon. Storage condiƟons (Ɵme and temperature) of the protein extracts are important and should be menƟoned in the kit insert informaƟon

This comment indicates that clarificaƟon may be needed on the descripƟon of the nested designs, as it was not intended for any given extract to be analyzed on mulƟple days. The enƟrety of the analysis of each test porƟon would be conducted on the corresponding day. The “E” notaƟon in the diagrams was intended to indicate whether each test porƟon delivered a single ELISA measurement from using a single well (E1 only), or each test porƟon delivered two ELISA measurements from using two wells (E1 and E2). We have made edits to clarify this disƟncƟon in each of the four nested designs shown. The working group agrees that shipping condiƟon evaluaƟons are important for test kit manufacturers to conduct. However, given that it may be challenging to define and implement study design requirements and acceptance criteria for such studies, we have made edits that strongly recommend method developers conduct evaluaƟons as appropriate for their specific test kits.

the robustness study should include shipping condiƟon of the test kit