ASSAY FOR PLASMA HEPARIN USING A SYNTHETIC PEPTIDE SUBSTRATE FOR THROMBIN - INTRODUCTION OF FLUOROPHORE AMINOISOPHTHALIC ACID, DIMETHYL ESTER

A precise sensitive method for assay of plasma heparin anticoagulant activity using a synthetic fluorescent tripeptide, H-D-phe-pro-arg-5-amidoisophthalic acid, dimethyl ester, as a substrate for thrombin is described. The assay procedure is designed for the routine monitoring of plasma heparin activity in the therapeutic anticoagulant range with smaller and larger activities also detectable. Heparin is measured in 5 μl of patient plasma (not defibrinated) with assay precision equal or superior to standard clotting assay measurements. © 1978.