Purification and Partial Characterization of Immunoglobulin M from Carassius auratus Serum and Skin Mucus

serum IgM in Carassius auratus was purified by precipitation of ammonium sulfate saturated solution followed by Sephadex G-200 chromatography.Then we made rabbit polyclonal antibody against serum IgM and linked it to Sepharose 4B to made affinity column,with which IgM was separated from skin mucus.The results showed that many other proteins were removed from serum by precipitation of ammonium sulfate,IgM could reach a purity of above 80% by Sephadex G-200 chromatography purified further,and the molecular weights of its heavy chain and light chain were 79 kDa and 25 kDa respectively.The rabbit polyclonal antibody affinity column had good capacity of purifying skin mucus IgM,whose heavy chain was 88 kDa.The rabbit antibody only recognizes the heavy chain of serum and skin mucus IgM by Western blot analysis.The result of ELISA indicated that IgM concentration in serum was higher in spring and summer than in autumn and winter.