Electroimmunoassay of factor VII antigen.

A clear precipitating arc of factor VII antigen appeared by immunoelectrophoresis using 125I-labelled anti-factor VII antibody incorporated in the Laurell plate to enhance the sensitivity. A plasma sample could be electrophoresed directly on 1% agarose containing 1% rabbit anti-human factor VII antiserum, 0.1% 125I-labelled anti-human factor VII specific IgG and 0.5% polyethyleneglycol 6000, and after washing, autoradiographed at -70 degrees C for 24 hr. A distinct rocket was seen from 45 ul standard reference plasma to 16-fold after auto-radiography. Of 4 patients with congenital factor VII deficiency, 3 patients had no detectable factor VII antigen, one patient had reduced factor VII antigen.