Quality control (QC) is required testing to ensure that products or processes are meeting standards. QC testing is performed on blood products to measure the quality of the component manufacturing process. Platelet count and pH in apheresis and whole blood-derived platelets, fibrinogen and factor VIII level in cryoprecipitate, and residual white blood cell count after leukocyte reduction of platelets or red cells are just a few of the QC measures evaluated by blood banks. If products fail minimum QC standards, blood banks must assess the issue and intervene to ensure that the products are being properly prepared. QC is often confused with quality assurance and quality management.