en Immunology Immunology Original Research: Basic Science in Medicine Original Research: Basic Science in Medicine Mycobacterium tuberculosis (H37Rv strain) was used in this study. The bacterial cells were disintegrated by sonication. The separation and characterization of the soluble molecules were attempted by various techniques including gel filtration, ion exchange chromatographies and polyacrylamide gel electrophoresis, using SDS and 2ME. Eight protein molecules with molecular weights ranging from 6.3 up to 204 kD were identified. Following reduction of the 204 kD molecule with 2ME, six smaller molecules with 12a, 12b, 21, 29,45 and 81.5 kD molecular weights were obtained. All isolated protein molecules were able to induce delayed hypersensitivity skin reaction in sensitized guinea pigs and proliferation of T-cells in vitro. Regarding the fact that an effective protective immunity in tuberculosis is dependent mainly on T-cell response, it is suggested that the molecules isolated in this study may be useful in conceiving a vaccine and/or diagnostic tests for tuberculosis. M. tuberculosis, Protein Antigens, CMI Responses, Purification 291 297 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-1-415&slc_lang=en&sid=1 A ZAVARAN HOSSEINI 20031947532846005284 20031947532846005284 Yes From the Department of Immunology, Tarbiat Modarres University MB ESLAMI 20031947532846005285 20031947532846005285 No the Dept. of Immunology School of Public Health, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran. M JALALI 20031947532846005286 20031947532846005286 No the Dept. of Biochemistry, School of Public Health, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran.