Purification and identification of turkey immunoglobulin-A

Turkey immunoglobulin-A (IgA) was isolated from bile, intestinal secretions, and serum by affinity chromatography using monospecific anti-turkey IgA coupled to CNBr-activated Sepharose. The isolated immunoglobulin was antigenically distinct from IgM and IgG. The purity of IgA was demonstrated by immunodiffusion, immunoelectrophoresis, and analytical ultracentrifugation. The predominant forms of polymeric IgA in bile and intestinal secretions had respective So20w values of 16.1 and 15.2. Larger polymers (25-26S) were also present. Two molecular forms (8.5S and 17S) were found in serum. The 8.5S peak was higher than the 17S, indicating a greater concentration of 8.5 S.