Abstract: | Chromogenic substrates were used to assay prekallikrein, prothrombin and factor X. Plasma prekallikrein was contact activated and allowed the splitting of HD-Pro-Phe-Arg-PNA which has affinity for plasma kallikrein. Prothrombin was assayed in various ways (immunologically, after activation with Ecarin or in a less specific way). Determination of factor X is considered as a possible specific method in the monitoring of coumarol therapy. |