Gel Isoelectric Focusing of Selected Bovine Immunoglobulins

Abstract

Commercial IgG1, IgG2, and IgM bovine immunoglobulin fractions were relatively homogeneous by acid polyacrylamide gel-electrophoresis and immunoelectrophoresis. However, isoelectric focusing in polyacrylamide gels with ampholytes covering wide and narrow pH gradients revealed heterogeneity among IgGl and IgG2 species with estimated isoelectric points in the pH ranges of 5.5 to 6.8 and 7.5 to 8.3, respectively. IgM was not resolved by gel isoelectric focusing. IgGl and IgM were tentatively identified as the major and minor immunoglobulin components, respectively, of bovine colostrum whey. © 1972, American Dairy Science Association. All rights reserved.