Preparation of Bovine Immunoglobulins and Free Secretory Component and Their Specific Antisera

Abstract

The preparation of bovine IgG1, IgG2, IgM, secretory IgA and free secretory component is described. The methods require a minimum of equipment and utilize four basic procedures: precipitation, electrophoresis, gel filtration, and DEAE chromatography. The electrophoretic and immunochemical techniques described for assaying the purity of the various preparations are sensitive and those utilizing radial or immunodiffusion are inexpensive. The immunoelectrophoretic and disc electrophoretic patterns for each preparation are diagnostic and highly reproducible. Methods are described for the preparation of monospecific antisera against each preparation and a polyvalent antiserum against bovine immunoglobulins. In addition, the presence of 7 S IgM in bovine serum, and proteolytic digestion fragments and aggregates of IgG in whey, are described. The occurrence of these immunoglobulin units helps to explain the complicated immunoelectrophoretic patterns often observed in bovine body fluids and also the multiple ring phenomena obtained during radial diffusion assay for immunoglobulins in the cow. © 1972, American Dairy Science Association. All rights reserved.