The FITC-QC Slide is an independent quality control check for assessing the level of fluorescent intensity provided by each laboratory’s microscope. Each slide has five different wells of microbeads containing FITC, ranging from 4+ to +/- in intensity. The concentration of FITC in the microbeads is calibrated by flow cytometry. The FITC-QC Slide allows the laboratory to verify proper performance of the optical system of their fluorescent microscope before beginning each run. This conforms to the NCCLS-approved guidelines as outlined in document I/LA2-A.