[Quantitative determination of factor VIII antigen with an enzyme immunoassay]

We describe an enzyme-immunoassay for the determination of factor VIII antigen. After representation of the isolation of proteins the enzyme-immunoassay is presented. The principle of the method is the following: Test plasma is mixed with rabbit antibody in excess and incubated at 37 degrees C. The incubation mixture is added to polystyrene tubes, which are coated with human factor VIII. The rabbit antibody is available to adhere to factor VIII coating the tube and can be detected with an enzyme-labeled antibody to rabbit IgG. This method is sensitive to 7.8 . 10(-3) U/ml factor VIII antigen; the variation coefficient is 10.9%.