Haemoglobin-coated charcoal for estimation of gastric intrinsic factor
Vatn, M.H.
Scandinavian Journal of Gastroenterology 8(8): 755-760
1973
ISSN/ISBN: 0036-5521 PMID: 4771117 Document Number: 60919
The different steps of the charcoal method, with human haemoglobin as coating material, were examined. Within and between estimations precision of 3.7 and 4.5%, respectively, was achieved. The vitamin B-12 binding capacity and different amounts of gastric juice in the range of 20 to 80% of the vitamin B-12 standard were almost linearly related. The studies indicated that neutralised gastric juice should be incubated with antiserum for at least 2 min, and vitamin B-12 for 1 h, at room temperature and also that the coated charcoal method is dependent on pH and is unreliable for examination of binding of intrinsic factor and B-12 at extreme pH values. Haemoglobin-, serum- and dextran-coated charcoal gave similar results for estimation of intrinsic factor activity; the estimated unspecific B-12 binding activity was higher with dextran than with haemoglobin and serum.