Patent ID: 7803570

Claim:
A method for determining the concentration of a thrombin inhibitor in a non-turbid body liquid or a non-turbid extract from a body liquid, comprising a) obtaining a body liquid from a living body and optionally separating turbid matter from said body liquid; b) obtaining a solution or a mixture, by adding to the non-turbid body liquid of (a), a coagulation-inhibiting substance which does not interfere in the transformation of educt prothrombin into an active meizothrombin or meizothrombin-des fragment 1 (Mtdesfg1) product; a chromogenic or fluorogenic substrate which is not dissociable by said active meizothrombin or said Mtdesfgl product; and a substance which dissociates prothrombin into meizothrombin or Mtdesfgl optionally together with prothrombin; c) subjecting the solution or mixture of (b) to a wavelength-selective light absorption or light emission measurement as a function of the time; and d) comparing the per time unit absorption or emission measurement of (c) to a standard; and e) determining the concentration of said thrombin inhibitor from d).