Quality Control of the One‐stage Factor Viii (Viii:c) Assay in the Coagulation Laboratory

In this chapter measures are described that should be taken to ensure the reliability and accuracy of one‐stage assays of Factor VIII coagulant activity (VIII:C). The first part deals with requirements for reagents, test conditions and procedure. The second half is dedicated to the problem of interlaboratory variation of Factor VIII assays; the results of a multicentre collaborative study on the quality control of Factor VIII concentrates are presented.