Application of mechanical impedance measurements to the study of dysfibrinogens

Most techniques of clot detection do not give information about the mechanical properties of the forming clot. A procedure was developed by which the dynamic loss modulus, or mechanical impedance, of a solution of fibrinogen could be continuously monitored during clot development. This method was then applied to the analysis of purified preparations of normal fibrinogen and two dysfibrinogens. Both thrombin and reptilase were used as clotting agents, and unique tracings of clot impedance vs. time were generated for each dysfibrinogen. The functional defect was known in each case, and the clot impedance tracings were able to distinguish between abnormalities in the release of fibrinopeptides A and B. Mechanical impedance measurements were shown to complement other types of analyses now used in the characterization of dysfibrinogens. In particular, they distinguished between dysfibrinogens that appeared similar by more conventional laboratory methods.