Radioimmunoassay of intestinal goblet cell mucin
Forstner, J.F.; Ofosu, F.; Forstner, G.G.
Analytical Biochemistry 83(2): 657-665
1977
ISSN/ISBN: 0003-2697 PMID: 603048 Document Number: 123304
A double-antibody radioimmunoassay was developed for the measurement of rat intestinal goblet cell mucin. Labeling of the mucin was achieved by mild periodate oxidation and sodium boro[3H]hydride reduction. Tracer amounts (0.5 ng) of labeled mucin were incubated with specific rabbit antibody in the presence of unlabeled mucin standards or extracts of intestinal tissues or their secretions. Normal rabbit serum and sheep antiserum to rabbit Ig(immunglobulin)G were used as a double-antibody system to precipitate the mucin-antibody complex. The radioimmunoassay proved to be suitable for measuring 3-80 ng of mucin in intestinal homogenates (soluble fraction), acid-precipitable glycoprotein (after solubilizaton and neutralization), and purer mucin fractions prepared by precipitation of homogenate supernatant solutions with cetyltrimethylammonium bromide. This appears to be the 1st study in which a mucin was measured by radioimmunoassay.