An Ultrastructural Investigation of the Fibrin Clot Utilizing Ferritin-labelled Anti-human Fibrinogen Antibody.

By JAMES G. WmTE, WILLIAM KRIVIT AND ROBERT VERNIER T HE PRIMARY PURPOSE of the complex mechanism of coagulation is to convert soluble fibrinogen molecules into a stable meshwork of fibrin. Appreciation of the macro-molecular architecture of fibrin is essential to an understanding of how clot formation fulfills its role in hemostasis. An electron microscopic study, combining the use of immune methods, has been applied to the ultrastructural evaluation of fibrin formation. Ferritinlabelled antihuman fibrinogen antibody ( fer-A.F. antibody) incubated with plasma during clot formation specifically stains the developing fibrin strands. Periodic bands, indicative of a high degree of order, are produced by the ferritin conjugated antibody on the intrinsic cross striations of fibrin. These observations suggest the mode by which fibrinogen molecules unite to form the fibrin strand.