Preparation of a heterologous antiserum for the determination of von Willebrand factor in human plasma.

A simple method for the preparation of rabbit antiserum against human von Willebrand factor (vWF) from commercial lyophilized factor VIII concentrate is described. vWF antigen (vWFAg)-like protein was obtained by gel filtration of the concentrate on Sepharose 4B. A combination of measurements of protein content by absorbance at 280 nm, and of vWFAg by electroimmunoassay using a commercial antibody, provided the data needed to select the Sepharose-filtered fractions with the highest concentrations of vWFAg-like protein. The immunization scheme used induced high antibody titers from the 45th to the 126th day after the first immunization. The resulting antiserum showed a performance similar to that of a commercial preparation in terms of vWFAg determination by electroimmunoassay and two-dimensional crossed-immunoelectrophoresis.