A comparison of two methods for the immunoassay of intrinsic factor.

The intrinsic factor content of 263 samples of gastric juice was determined by immunoassay using charcoal absorption and by immunoelectrophoresis on acrylamide gel. There was good correlation between the results of the two techniques and, with a few exceptions, both made it possible to predict which patients would have malabsorption of radioactive vitamin B(12). Of the two methods, immunoassay using charcoal absorption generally gave the higher readings. Further study showed that this could not be attributed to the recognized difference in the principles of the two methods but that it was more likely to be due to the dissimilarity of the experimental conditions.