ABSTRACT
The genus of sarcocystis, zonotic parasites, have two hosts in their life cycle. They have also special importance in industrial veterinary. The serological tests are the best methods for detection of the parasite. This research was planned for isolation of sheep sarcocystis specific protein for using in serological laboratory tests. The infected muscles of sheep carcass were collected from Tehran slaughter house and transferred to our laboratory. The sarcocystis were isolated from the infected muscles and crude antigen was prepared. The crude antigen was fragmented by serial dilution of ammonium sulfate solution and followed by size exclusion chromatography. Crude antigen was electrophoresed by SDS-PAGE and its protein bands were detected by commassi brilliant blue staining. We used different concentrations of ammonium sulfate for precipitation and after by size exclusion chromatography, a 35kDa protein band was separated and observed by SDS-PAGE. The protein band of sheep sarcocystis which can be used as antigen in serological methods was parified and detected