COMPARISON OF 3 DIFFERENT PRIMER PAIRS FOR THE DETECTION OF MYCOBACTERIUM-TUBERCULOSIS BY POLYMERASE-CHAIN-REACTION IN PARAFFIN-EMBEDDED TISSUES

SETTING: More than five different primer pairs have been used for the detection of Mycobacterium tuberculosis deoxyribonucleic acid (DNA) wi th the polymerase chain reaction (PCR). OBJECTIVE: The sensitivity and specificity of PCR were evaluated using three different primer pairs in the detection of M. tuberculosis in paraffin-embedded tissues. DESI GN: Thirty-eight tissue specimens from 23 patients were studied. Eight een samples were obtained from 10 tuberculosis patients, and 20 sample s obtained from 13 patients with other diseases were used as negative controls. DNA extracted from paraffin-embedded tissues was used direct ly for PCR amplification using primers 1S1 and 1S2 to amplify a 123 ba se pair (bp) region of IS6110, sjMT3 and sjMTr2 to amplify a 281 bp re gion of protein antigen b, and INS1 and INS2 to amplify a 245 bp regio n of IS986. Each amplification was performed double-blinded and repeat ed three times including positive and negative control samples. RESULT S: IS1 and IS2 gave a positive result in each of the double samples ob tained from eight tuberculosis patients and in the single samples obta ined in the two others, sjMT3 and sjMTr2 detected 13 of the 18 tubercu losis samples, and INS1 and INS2 detected only three of the 18. CONCLU SION: These results highlight the importance of selecting appropriate primers to obtain high sensitivity in detecting M. tuberculosis in par affin-embedded tissues by PCR.