A recently introduced fluorescence polarization immunoassay (FPIA) for determination of cyclosporine A in serum and plasma is discussed with regard to its use for whole-blood samples, with and without hemolysis before the assay. The performance characteristics of the modified method are highly satisfactory (within-run CVs 2.06 to 5.50% and 1.99 to 3.39%, respectively; long-term between-run CVs under routine conditions 5.73 to 8.95%). The limit of detection is 30 micrograms/L. Results agree well with those obtained with the RIAs compared, but the modified FPIA is more convenient and faster.
Cyclosporins Fluorescence Polarization