Sensitivity of the molecular diagnostic tests of extrapulmonary tuberculosis largely depends upon the efficiency of DNA extraction methods. The objective of our study was to compare three methods of extracting DNA of Mycobacterium tuberculosis for testing by polymerase chain reaction. All three methods; heating, heating with sonication and addition of lysis buffer with heating and sonication were implicated on 20 extrapulmonary samples. PCR positivity was 2 (10%), 4 (20%) and 7 (35%) in the samples extracted by heating, heat+sonication and heat+sonication+lysis buffer method respectively. Of the extraction methods evaluated, maximum PCR positive results were achieved by combined heat, sonication and lysis buffer method which can be applied in routine clinical practice.

Ibrahim Med. Coll. J. 2012; 6(1): 9-11

Key words: Tuberculosis, extrapulmonary, DNA, extraction

Address for Correspondence:Dr. Khandaker Shadia, Assistant Professor, Department of Microbiology, Ibrahim Medical College, 122 Kazi Nazrul Islam Avenue, Dhaka 1000, Bangladesh, e-mail: [email protected]