Determination of cyclosporin A in 20% ethanol by a magnetic beads-based immunofluorescence assay

A rapid magnetic beads-based immunoassay for the immunodepressant drug cycl osporin A (CsA) has been developed. The method allows CsA determination in medium with a higher content of ethanol compared to conventional immunochem ical techniques due to increased antibody stability. Monitoring of the drug in ethanol extracts from patient's whole blood without many-fold dilution with aqueous buffer is possible. The assay has adequate specificity and sen sitivity for CsA to be suitable for the routine monitoring of therapy, (C) 1999 Academic Press.