AOAC Guidance on FA Immunoassay Validation (August 2023)

3.3.6. Sensitivity: Probability of a (+) response at a given concentration; POD(c) 182 4. Required Method Information 183 4.1. General Method Information 184 4.1.1. Scope 185 The information described in this section is required for all immunoassay-based food allergen methods, 186 including both quantitative and qualitative methods, submitted for AOAC OMA or PTM review. 187 4.1.2. Applicability Statement 188 Method developers must provide an applicability statement describing the method’s target analyte, 189 measurand, matrices within scope, and important limitations. 190 4.1.3. Standard Method Performance Requirements 191 If the method is intended to conform to an existing Standard Method Performance Requirements 192 (SMPR) document, the SMPR citation must be provided. In addition to the information described in this 193 document, methods submissions must provide any additional details mandated by relevant SMPRs. 194 4.1.4. Analyte and Measurand 195 4.1.4.1. The analyte and measurand must be clearly defined. 196 4.1.4.2. The term ‘analyte’ is better known and more widely used than ‘measurand’. ‘Analyte’, or the 197 name of a (bio)chemical substance or compound, are terms sometimes used for 'measurand', 198 incorrectly because the aspect of quantity is omitted. Two examples cited by Eurachem (8) 199 illustrate the difference between the two terms. The first is very simple, when analysing for 200 glucose in plasma, important for diabetics, the analyte is glucose and the measurand is ‘the 201 amount of substance (concentration) of glucose in plasma’. Another medical laboratory 202 example, a 24-hour urine protein analysis, which can help detect disease or other problems. 203 The analyte is protein and the measurand is ‘mass of protein in 24-hour urine’. Note the 204 protein is likely to be measured by a dye-binding method and reported in mg/100mL hence 205 the volume of urine collected must be known to calculate the mass of protein in the 24-hour 206 sample. Other examples are given by De Bièvre (1). 207 4.1.4.3. The International Vocabulary of Metrology, VIM (4), notes that changes in the measuring 208 system and the conditions under which the measurement is carried out might result in the 209 quantity being measured differing from the measurand-as-defined. This is particularly 210 important in allergen analysis . Moreover we need to have regard to and report sufficient 211 detail about the method and units to enable others to make sensible use of the reported data. 212 The following Table ( Table 1 ) illustrates the most common measurands, analytes, measuring 213 systems and units relevant to allergen analysis. 214