Brucellosis is a major bacterial zoonosis of global importance. The conventional serological tests viz. RBPT, SAT and CFT have certain inherent problems which are circumvented with the development of ELISA. But till date species specific conjugate required for ELISA in buffaloes is not available. In the present study, Fluorescence Polarization Assay was standardized using indigenously prepared antigen for the diagnosis of brucellosis in buffaloes. The OPS was extracted from B. abortus S99 and conjugated with FITC to obtain FPA antigen. The fluorescence intensity of the FPA antigen was...