OBSERVATIONS ON THE PRECIPITATION REACTION IN A DOUBLE-ANTIBODY IMMUNOASSAY FOR INSULIN

Abstract

ABSTRACT The effects of human serum and ethylenediaminetetraacetate (EDTA) on the precipitation stage of a double-antibody immunoassay for insulin have been studied. Human serum consistently reduced the rate of precipitation of bound insulin by rabbit antiserum and the results obtained with modified human serum suggested that this effect was due to complement. Under certain conditions, EDTA was found to accelerate the precipitation of antibody-bound insulin and some implications of this finding to the double-antibody method of assay are considered.