Reactivity of fibrinogen derivatives with antisera to human fibrin D-dimer and its gamma-gamma chain remnant.

Highly purified D-dimer was obtained from plasmin digest of human cross-linked fibrin. After reduction of its disulfide bonds, the gamma-gamma chain remnant, containing cross-linking site, was then isolated by ion-exchange chromatography on CM-cellulose. Antisera obtained by immunizing rabbits with D-dimer and its gamma-gamma chain remnant contained a small population of antibodies which specifically reacted with D-dimer. Thus, a specific radioimmunoassay system allowing detection and quantitation of D-dimer in the presence of fibrinogen and monomeric fragment D was made possible.