[A rapid and precise determination of fibrinogen and its cleavage products (author transl)].

A method is described for the quantitative determination of fibrinogen equivalents in citrated blood before and after removal of the fibrinogen by coagulation. The method employs an immunological reaction, which is measured by mechanized nephelometry. Thus the sum of all the fibrinogen equivalents can be compared with the concentration of "cleavage products". The difference between the two readings represents the concentration of coagulable fibrinogen. For the fibrinogen concentration of 11.15 mg/l, variation coefficients of 2.81% in series and 3.31% for day to day were obtained. The accuracy of a new method was tested under conditions of fibrinogenolysis, and in the presence of heparin, by comparison with simple radial immunodiffusion, and with the "coagulation physiological rapid method for the determination of fibrinogen" after Clauss ((1957), Acta-Haematol, 17, 237-246). In addition 180 citrated blood samples of different patients were compared with the simple radial immunodiffusion, the method of Clauss and the new method. Only the new rapid method appears to measure plausible fibrinogen values, and permits a clear differentiation between coagulable and non-coagulable fibrinogen equivalents. It can be recommended for clinical practice.