中文摘要：

目的应用茎环分子探针检测结核分枝杆菌耐异烟肼katG315codon点突变，运用荧光分光光度计直接观测液相中探针与katG315codon扩增产物杂交后的荧光信号，并与测序结果比较以验证该检测方法。方法运用软件：Beacondesigner设计katG基因包含315codon的茎环分子探针，建立其扩增体系及分子信标芯片检测方法；对扩增产物测序并作比较。结果通过荧光分光光度计观测到结核标准株及耐异烟肼PCR产物与探针杂交后荧光信号差异有统计学意义；16株耐异烟肼组与10株H37RV标准株对照组荧光信号强度比较，耐异烟肼组315codon突变检出率为44％，茎环分子探针检测方法与测序法符合率97．5％。结论茎环分子探针技术是一种具有高灵敏核酸点突变检测技术；荧光分光光度计液相荧光检测方法与测序法符合率较好。

英文摘要：

OBJECTIVE To detect 315 codon of mutation site in katG of isoniazid （INH）-resistant Mycobacterium tyberculosis （MTB） by stem-ring molecular probe quickly and detect out the fluorescence sign of hybridization between amplified products of katG 315 codon and probe in liquid by fluorescence spectrophotometer. The results were confirmed by sequencing. METHODS The software, Beacon designer, was used to design the katG 315 codon stem-ring molecular probe and the amplification system, and the relationship between the way and sequencing of the amplification products were compared. RESULTS The difference between PCR products from standard strain and INH-resistant one was significant in detecting the fluorescent light by use of fluorescence speetrophotometer. We detected fluorescent light signal between the 16 INH resistant strains and 10 H37RV standard strains. The resistant rate to INH detected was about 44%, and the rate of coincidence was about 97.5% . CONCLUSIONS The stem-ring molecular probe technology show high sensitivety in detecting mutation site of nucleic acid. The rate of coincidence is good between fluorescence spectrophotometer way and sequencing.