Assay of intrinsic-factor activity of human gastric juice with zirconyl phosphate gel

A method employing zirconyl phosphate gel has been described for measuring the IF activity of human GJ. IF and B 12 binders which do not possess IF activity are differentiated by the use of IF specific antibody found in serum of PA patients. This antibody neutralizes the B 12 combining site of IF, but not the B 12 combining site of other binders present in GJ. For all practical purposes, no IF activity was found in the GJ obtained from 24 patients with pernicious anemia. GJ obtained from 11 controls of approximately the same age group as the PA patients contained about 50 times more IF than the PA gastric juice. There were no overlapping values.