Extraction and purification of Jo-1 antigen / 基础医学与临床

ABSTRACT

Objective To improve the purifying method of Jo-1 antigen from rabbit thymus used for detection of anti-Jo-1 antibody by dot-blotting immunoassay(DB).Methods The rabbit thymus glands were cut into pieces,homogenized and extracted by PBS.Total protein was precipitated by acetone to get acetone powder(RTAP).The RTAP was solved in PBS and separated by an by anti-Jo-1 IgG affinity column.Results 5～7 g RTAP was obtained from 100g rabbit thymus glands.There was 19%～24% of protein in RTAP.Jo-1 antigen was enriched around 1900 folds through affinity chromatography,with 2.5% recovery of antigenic activity.In this preparation,there were several bands on SDS-PAGE,but only one band about 50 ku,reacted with anti-Jo-1 antisera on immunoblotting.Dot-blotting also showed that the antigen only reacted with Jo-1 antisera.The purified Jo-1 antigen was not stable for long time,but the antigenic activity could maintain for a long time when there was MgCl2 in the solution.Conclusion Affinity chromatography was a simple and easy method for purifying Jo-1 antigen from rabbit thymus.The antigen purified by affinity chromatography could meet the requirement for detecting Jo-1 antibody bydot-blotting.