Use of Insoluble Antibody for Quantitative Determination of Small Amounts of Immunoglobulin

Abstract

A quantitative inhibition test for individual proteins has been developed using isotopically labeled ¹²⁵I protein and insoluble antibody. Antibodies, reacting specifically with individual human immunoglobulins (IgG, IgA, IgM, κ or λ), were made insoluble by coupling to bromacetyl cellulose by the technique of Robbins, Haimovich and Sela. Radioiodinated immunoglobulins were used with insoluble antibody in quantitative inhibition tests to measure the human immunoglobulins. The test is rapid, gives reproducible results, and is more sensitive than gel diffusion precipitation assays.