Evaluation of a Commercial Kit for the Radioimmunoassay of Fibrinopeptide A

Measurement of fibrinopeptide A (FpA) provides a sensitive and specific marker of thrombin generation and is important in the investigation of the mechanisms involved in thrombosis and hemostasis. However, current methods available for determination of FpA by radioimmunoassay (RIA) require rigorous method development. Recently, a commercial kit (Mallinckrodt Corp: M-Kit) for the RIA of FpA has become available which contains all the necessary reagents for the assay. We evaluated this kit and compared it to an assay prepared from a commercial kit (IMCO Corp: I-Kit) which contains only the raw materials. Both assays had similar characteristics and duplicate plasma samples assayed using both methods were not significantly different. Separation of FpA from fibrinogen using bentonite slurry (M-Kit) proved superior to the ethanol precipitation method (I-Kit). The complete kit (M-Kit) will provide the routine hemostasis laboratory with an RIA for FpA which is immediately available.