Surplus test materials from the batch used for the PT may be available for purchase as quality control (QC) samples. These QC samples may be used for troubleshooting poor performance in the PT, training of new staff, method development or generating QC charts. Fapas QCs have an associated datasheet which provides the same data of assigned values and performance limits as in the PT. The stability assessment of QC samples is the same as that for the PT.
