A simple assay of intrinsic factor-vitamin B12 complex employing the binding intrinsic factor antibody.
The reaction between binding intrinsic factor antibody and intrinsic factor-vitamin B(12) complex has been studied. Initially in the zone of antibody excess, the relationship between the amount of antigen present and the amount of antigen-antibody complex adsorbed onto zirconium phosphate gel was linear. With increasing amounts of antigen, the curve departed from linearity and reached a plateau. The linear portion of the reaction forms the basis of a simple and reproducible assay for quantitating intrinsic factor to which vitamin B(12) has already been bound. The assay provides a method for studying the fate of intrinsic factor-vitamin B(12) complex during digestion and absorption. In two normal subjects given radioactive vitamin B(12) orally, aspiration of ileal contents showed that only 50 to 70% of the radioactivity was bound to intrinsic factor at that level.
D000327:Adsorption; D000906:Antibodies; D000936:Antigen-Antibody Complex / Q000032:analysis; D001665:Binding Sites; D003036:Cobalt Isotopes; D004063:Digestion; D005750:Gastric Juice / Q000032:analysis / Q000276:immunology; D006801:Humans; D007118:Immunoassay; D007408:Intestinal Absorption; D007419:Intestinal Secretions / Q000032:analysis / Q000276:immunology; D007437:Intrinsic Factor / Q000032:analysis*; D014805:Vitamin B 12 / Q000032:analysis* / Q000378:metabolism; D015040:Zirconium
D000906:Antibodies; D000936:Antigen-Antibody Complex; D003036:Cobalt Isotopes; D007437:Intrinsic Factor; D015040:Zirconium; D014805:Vitamin B 12