Microbiology-PTM-OMA_Modules_1-5

Matrix Study Designs – Recent Trends

• Candidate methods must always be confirmed • 1 colony from 1 agar plate per test portion is acceptable to follow through to  identification. • All instrument platforms must be tested in the matrix study. • Composite test portions (e.g., 375 g) for the candidate method are  compared to 25 g test portions for the reference method (if applicable). • Temperature claims • Enrichments ‐ if both incubation temperatures have a ± 1°C range and incubation is  conducted at 41.5°C (EU), then it is acceptable to claim for 42°C in the US • Selective agars – incubation at 36 ± 2°C is acceptable if the US method is 35 ± 1°C  and the EU method is 37 ± 1°C. • ISPAM approved equivalence of 35°C and 37°C for  Salmonella primary enrichments.