AOAC Guidance on FA Immunoassay Validation (August 2023)

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5.3.2.2. Study Design, Data Analysis, and Reporting

The study design, data analysis, and reporting for the independent laboratory study should follow the same requirements described in the Matrix Study component of the Method Developer Study

(5.2.4).

5.4. Collaborative (Interlaboratory) Study 707 5.4.1. AOAC Requirements: Collaborative studies will adhere to all minimum requirements established 708 by AOAC in Appendix D. (12) The information in this section is provided to indicate where 709 additional specifications are required for food allergen method validation or to highlight particular 710 metrics and parameters relevant to the evaluation of food allergen methods. 711 5.4.2. Scope: The intent of a collaborative study is to establish relevant method attribute estimates that 712 can be expected when a method is used in practice, with a particular focus on precision 713 (repeatability and reproducibility) and recovery. (12) With respect to food allergen methods, 714 estimation of sensitivity (LOD and LOQ) is also within the study scope. 715 5.4.3. Number of Laboratories: 716 5.4.3.1. Based on AOAC Appendix D guidelines, studies must have a minimum of 8 laboratories 717 submitting valid data (to avoid unduly large confidence bands about the estimated 718 parameters). (12) 719 5.4.3.2. To minimize potential bias, no more than 25% of the laboratories with data included in the 720 final dataset may come from the same organization. For this purpose, the term organization 721 includes companies (test kit manufacturers, method developers, food processors, etc.), 722 regulatory bodies, government agencies, or any other body. (9) 723 5.4.4. Test Materials: 724 5.4.4.1. Incurred test materials are required for estimation of precision, sensitivity, and recovery. 725 See Annex A for description of best practices for incurred matrix preparation. 726 5.4.4.2. Appendix D requires a minimum of 5 materials be used in the collaborative study. (12) Three 727 materials are allowed but only when a single specification is involved for a single matrix. For 728 the purposes of this requirement, a material is defined as a combination of the test 729 component, matrix, and concentration to which the method performance parameters apply. 730 5.4.4.3. Two blind-coded replicate samples should be analyzed by each laboratory for each test 731 material (i.e., each matrix-concentration combination). For each matrix, the concentration 732 levels must include a blank (zero) and a level at less than or equal to two times the LOQ 733 stated in the kit insert. The remaining concentrations should be distributed throughout the 734 quantification range. (9) 735 5.4.5. Data Analysis 736 5.4.5.1. All individual data values must be reported. 737 5.4.5.2. Data analysis will be conducted according to the procedures described in Appendix D. (12) 738 Specifically, the following must be performed and reported: 739 5.4.5.2.1. Outliers should be evaluated as described in Appendix D. 740 5.4.5.2.2. Recovery must be reported, with calculations using the known quantity of target 741 present in incurred test materials based on gravimetric calculations and accounting 742