title: Chromogenic substrate spectrophotometric assays for the measurement of clotting function.
abstract: Spectrophotometric assays for the measurement of coagulation factor activities in plasma have been developed using a relatively specific chromogenic substrate for thrombin. The tissue-factor-activated assay system involves the activation of factors VII and X and prothrombin. The surface-activated assay system involves the activation of factors XII, PK, XI, IX, VII, X and prothrombin using factors V and VIII as cofactors. The thrombin generated subsequent to activation in these two assay systems is measured via its activity on the chromogenic substrate Sarc-Pro-Arg-pNA. These spectrophotometric assays provide a higher degree of sensitivity as compared with the clotting time assays. The tissue-factor-activated system provides a sensitive method for monitoring coumarin therapy. The surface-activated assay system can detect deficiencies of all the factors measured by the conventional APTT assay system, as well as factor VII. Furthermore, this assay provides a sensitive method for monitoring heparin therapy.
mesh_terms: D000818:Animals; D001777:Blood Coagulation; D002417:Cattle; D002863:Chromogenic Compounds; D005168:Factor VII Deficiency / Q000097:blood; D006493:Heparin / Q000494:pharmacology; D011817:Rabbits; D013053:Spectrophotometry; D013917:Thrombin / Q000378:metabolism; D013925:Thromboplastin / Q000378:metabolism
chemical_list: D002863:Chromogenic Compounds; D006493:Heparin; D013925:Thromboplastin; D013917:Thrombin