Immunoblots of sequential plasma samples.

Plasma samples were drawn before and 1 to 72 hours after start of ancrod infusion, using monoclonal antibody MAb 2B5 against the neo–N-terminus of the fibrin α-chain for detection. Nearly no fibrin antigen is detected in the pretreatment sample. After start of ancrod infusion, there is a gradual increase in the amount of antigen detected by Mab 2B5, consisting of fibrin monomer and fibrin degradation products X and Y. A small amount of reactive material with higher molecular weight than fibrinogen is found in plasma samples drawn between 2 and 12 hours after start of ancrod infusion.