[Isolation and purification of bovine retina S-antigen]

Fresh bovine retinas were precipitated by ammonium sulfate, and further purified by the Sephadex G-200 column and the hydroxyapatite column. Through the SDS polyacrylamide gel electrophoresis and the isoelectric focusing gel electrophoresis, a single band of protein with molecular weight of 50,000 daltons, isoelectric point at 5.4-5.7, was identified as S-antigen. The yield of S-antigen from crude retina extract was 0.18%, higher than ever been reported. Guinea pigs were injected at the hind footpad with 5-30 micrograms of purified S-antigen which had been emulsified with an equal amount of complete Freund's adjuvant. There are severe uveitis findings in both clinical and pathological examinations. An experimental autoimmune uveitis animal model was successfully established. These results showed that it is an effective and rapid method for purification of retinal S-antigen.