[Rapid determination of protein C activity].

The diagnosis of Protein C (PC) congenital deficiency is of first importance because it leads, more frequently than Antithrombin III deficiency, to serious thromboembolic accidents in young patients, even when PC levels are slightly decreased (40 p. cent up to 60 p. cent). In order to measure PC activity, the authors developed a new method using the activator from Agkistrodon C. Contortrix snake venom and the synthetic chromogenic substrate CBS 65-25. Results obtained on plasma from normal individuals, congenital and acquired deficiencies, are comparable on the one hand, to those found with an ELISA method, and on the other hand with the clotting method, except for patients under anticoagulant therapy. This new rapid and sensitive method can be performed manually and is easily adapted on instruments used in clinical chemistry laboratories. This method is potentially available for routine use.