Accredited laboratories and laboratories operating in exempt states should contact their appropriate agencies to confirm any additional requirements for assessing analytical specificity. Analytical specificity should not be confused with clinical or diagnostic specificity, which reflects the ability of the assay to provide a negative/not detected result for a particular analyte in patients who do not have the corresponding disease. There is no minimum recommended number of samples to include in cross-reactivity or interference studies, although samples should be assessed at least in duplicate. For assessing cross-reactivity, sample types will typically include appropriate matrix spiked with a potentially cross-reacting organism or organism nucleic acid. The analytical specificity characteristic is generally not applicable for antimicrobial susceptibility test (AST) systems. If laboratories are introducing a new medium to their workflow, they should consider confirming that the new medium does not cause false AST results.