RESUMEN
Sarcocyst is one the most important protozoa belonged to apicomplexa. This parasite is prevalent among warm blooded animals throughout the world. In the present work, Sarcocystis gigantean was identified by amplification of 18SrRNA gene using PCR- RFLP. In this regard macroscopic cysts of sarcocystis were collected from esophagus and intra costal muscles of sheep in Shahriar slaughterhouse. Then genomic DNA of the parasites was extracted from specimens using phenol-chloroform method. 18S rRNA gene was amplified with specific primers. For RFLP two restricted enzymes of MspI and MobI were used and the patterns were analyzed accordingly. According to the resulted band, all the specimens were identified as Sarcocystis gigantean. This is the first report of molecular identification of Sacrocystis gigantean in Iran