Abstract: A new method for rapidly detecting restriction enzyme pattern of mycobacterium deoxyribonucleic acid (DNA) by capillary electrophoresis with laser induced fluorescence detection （CE-LIFD） was developed. Polymerase chain reaction was used to amplify a 439 bp fragment of 65000 (Mr) heat shock protein gene (hsp65) of mycobacterium. After digesting the amplification products by BstEⅡ and HaeⅢ respectively, the patterns of enzyme cleavaged products were detected by both CE-LIFD and agarose gel electrophoresis (AGE). The experimental parameters of CE were optimized. The restriction enzyme patterns of mycobacterium DNA can be detected under the optimum electrophoresis conditions: a coated capillary column with the length of 50 cm and 100 μm i.d., electrophoresis buffer of 45 mmol/L TBE (trihydroxymethyl aminomethane (Tris)-boric acid-ethylenediaminetetraacetic acid (EDTA)) and 11 kV running voltage. The restriction enzyme patterns for eight species of mycobacteria were studied. Relative standard deviations of the relative migration times of the DNA segments were less than 3.6%. Compared with AGE, CE is more outstanding in resolution and detection time, and it can be applied as a more effective means for DNA restriction enzyme pattern analysis.

Key words: restriction enzyme pattern, laser induced fluorescence detection, mycobacterium , capillary electrophoresis