Pooled dolphin sera (provided by Marine Animal Productions, Gulfport MS) were processed to separate and purify IgG, IgA, and IgM. Following an initial partial purification by ammonium sulfate precipitation methods, IgG was purified using Affigel-Blue affinity chromatography. After the precipitated sample was applied to the column, 45 fractions (3 ml/fraction) were collected. IgG came off the column with O.lM NaCl in 0.02M Tris buffer (pH 7.4) in fractions 17 to 22 with a peak at fraction 19. IgA and IgM were separated on the basis of molecular weight by Sephacryl-400 gel chromatography. Using 0.5M NaCl in 0.02M Sodium Phosphate (pH 7.3), IgM eluted from the column in fractions (1 ml/fraction) 26 to 31 with a peak at 31. IgA eluted in fractions 32 to 33 with a peak at 33. The trailing edge of the IgM peak caught the leading edge of the separation of IgA. Agarose electrophoresis was used to further check the purification. Individual rabbits were immunized by standard protocol with the purified immunoglobulins or whole serum. Specificity of the resulting antisera was determined by Graber-Williams immunoelectrophoresis and by ELISA. Any cross-reacting antibodies were removed by immunoabsorption.