AOAC GFA Stakeholder Program Meeting Book (August 27, 2023)

PAGE FIVE – SELECTIVITY STUDY

4.3 Selectivity Study The selectivity study is intended to provide information on potential sources of cross-reactivity and interference. The information related to cross-reactivity and interference should be reported in the validation report or in the package insert from the method developer

What is the definition of selectivity (Selectivity not in definitions) and occurs ~15 times in the document and might have more than one intended usage.

3.33 Selectivity: The degree to which the method can quantify the target analyte in the presence of other analytes, matrices, or other potentially interfering materials. Includes: Breadth: The ability of the method to detect gluten from multiple grain sources. Cross-reactivity: See definition of cross-reactivity above. Measurement Interference: A cause of significant bias in the measured analyte concentration due to the effect of another component or property of the sample which may result from non-specificity of the detection system, suppression of an indicator reaction, or inhibition of the analyte (CLSI_EP07A2E). An interference can be endogenous, present in the test material, or exogenous, introduced into the test material during the measurement process.