Immunologic adsorbents. I. Isolation of antibody by means of a cellulose-protein antigen

For the past several years we have been interested in devising methods that would afford practical procedures for the isolation and purification of antibodies from immune serums and in particular the isolation of non-precipitating antibodies from animal serums and allergic antibodies (reagins) from human serums.(1) The general approach has been to attempt to produce an insoluble protein antigen which would combine specifically with antibody to give a complex that could be dissociated into soluble antibody and insoluble antigen, which could then be separated by centrifugation. Attempts were made to confer insolubility on protein antigens such as ovalbumin and crystalline bovine serum albumin without destroying their antigenicity. Products were obtained by use of the usual denaturing agents, tannic acid, and bifunctional coupling reagents (e.g., tetrazotized benzidine), and also by coupling to an insoluble substrate such as phenolic resins or insoluble proteins (such as fibrin). However, in every case the resulting product either had lost too much native antigenicity (i.e., adsorbed serum always contained antibody which reacted with native antigen), was too soluble, or had too much power of adsorption for non-specific protein.