Serological precipitation method for studying biosynthesis and secretion of immunoglobulins by human peripheral blood lymphocytes.

A reproducible, serological method to quantify radiolabeled immunoglobulin (Ig) synthesized and secreted by human peripheral blood lymphocytes is described. In contrast to indirect precipitation (rabbit antihuman Ig and goat antirabbit Ig), the direct coprecipitation method using human IgG and rabbit antihuman IgG F (ab)2 showed much smaller, non-specifically precipitable radioactivity (i.e., 2 approximately 14%) without affecting Ig radioactivity.