Reactions of human and hog intrinsic factors with type I antibody to intrinsic factor.
A simple and rapid small-scale gel filtration method was applied in studies of type I antibody to intrinsic factor using radioactive vitamin B12 of high specific activity and purified human and hog intrinsic factor preparations, taking into account the unsaturated B12-binding capacity of the individual pernicious anaemia sera. This procedure allows the use of small amounts of reagents. Evidence was obtained for a close antigenic similarity of determinants of human and hog intrinsic factor. The use of purified intrinsic-factor preparations is important.