Comparison of fibrin networks in plasma and fibrinogen solution.

Mass-Length ratio of fibrin fibres (microT and microP) derived independently from turbidity and permeability respectively, in networks made in fibrinogen solution and plasma, have been compared under similar conditions of clotting. Amount of fibrinogen conversion to fibrin was similar in both systems when high thrombin concentrations were used. But networks in plasma had significantly thicker fibres (higher microT and microP) than those in fibrinogen solution. This difference arises from differing kinetics of fibrin assembly in the two systems. When lower thrombin concentration is used, fibrin fibre thickness (as indicated by microP and microT) is increased in fibrinogen solution but the fibrin content of the network remains unaltered. In plasma, on the other hand, the fibrin content of the network is decreased, microT remains relatively unchanged while microP increases. The thrombin concentration dependence of the fibrin content of the network in plasma and the bimodal distribution of fibrin fibre thickness explain the breakdown in correlation between microP and microT.