A novel enzyme immunoassay for quantitation of rat prothrombin in microsomal subfractions

An enzyme linked immunoassay (ELISA) for quantitation of rat prothrombin, based on a biotin-streptavidin alkaline phosphatase system is described. The assay utilizes rabbit antiserum raised against purified rat prothrombin. The assay was twenty fold more sensitive than a rat prothrombin assay based on amidolytic activity following activation by Echis carinatus venom. Results obtained with the two assays show good correlation. The ELISA is a valuable tool for quantitation of minute amounts of prothrombin in subcellular fractions and large series of plasma samples.