In this study, it was aimed to develop an Enzyme-Linked Immunosorbent Assay (ELISA) prototype to evalua- te humoral immune response against Brucella ovis by using different antigenic fractions from bacteria comparatively. For this purpose, four different antigens, namely Hot saline extract, Rough Lipopolysaccharide, Phage lysate 1, and Phage lysate 2 were used to test 84 sheep serum samples in ELISA. Seropositivity rates were, 14.3%, 13.1%, 10.7%, and 15.5%, respectively. Although the highest seropositivity rate was obtained by using the Phage lysate 2 antigen, it did not reach the level of statistical significance (χ2=0.89; P>0.05) difference between these antigens. It was concluded that in future studies, there would be a need for comparing the results of more serum samples tested in ELISA using Phage lysate 2 with the results of standard serological tests such as complement fixation test and agar gel immunodif- fusion test or available commercial ELISA kit. Thus, the potential possibility of commercialization of a new in-house ELISA prototype will be evaluated more realistically. Given the seropositivity rate of Brucella ovis infection obtained by using a small number of serum samples, a large-scale serological study with greater serum samples from different
parts of Turkey will reveal the real disease situation in our country.