Diagnostic Assays for Infectious

Validation is a process that determines the fitness of an assay, which has been properly developed, 6 optimised and standardised, for an intended purpose. Validation 8 includes estimates of the analytical and diagnostic performance 10 characteristics of a test. In the context of this chapter, an assay that 12 has completed the first three stages of the validation pathway (see 14 Figure 1 below), including performance characterisation, can be 16 designated as “validated for the original intended purpose(s)”1. To 18 maintain a validated assay status, however, it is necessary to carefully monitor the assay’s daily 19 performance, primarily through repeatability estimates of internal controls, to assure that the assay, 20 as originally validated, consistently maintains its performance characteristics. Should it no longer 21 produce results consistent with the original validation data, the assay may be rendered unfit for its 22 intended purpose. Thus, a validated assay is continuously assessed to 24 assure it maintains its fitness for purpose – as determined by assessments 26 of the assays validity in each run of the assay. 28