目的 :探讨HCVNS5b区酶切分型技术在临床上的应用。方法 :选用了HpaⅡ、Cfr10Ⅰ、AluⅠ、HhaⅠ、HaeⅢ、ApaⅠ、AvaⅡ、TaqⅠ、BstNⅠ、Sau 3AⅠ、StuⅠ、BalⅠ、SmaⅠ等 13种限制性内切酶 ,对已知2 3例 1b型和 17例 2a型样品进行酶切分析和验证。结果 :40例NS5b分型结果表明 2 3例 1b型中有AluⅠ特异切点 ,无 1a的BalⅠ切点和 2b的MboⅠ切点 ,17例 2a型中无A1uⅠ切点和 1a的BalⅠ及 2b的MboⅠ切点。StuⅠ可用于 1b型中基因变异诊断。结论 :HCVNS5b分型结果提示应用该分型技术 ,不仅达到了基因分型效果 ,而且还可检测基因变异 ,证实了我国存在着 1b和 1b混合感染状态 Objective: To investigate the clinical application of HCV NS5b restriction enzyme digestion technique. Methods: Thirteen kinds of restriction endonucleases such as HpaⅡ, Cfr10Ⅰ, AluⅠ, HhaⅠ, HaeⅢ, ApaⅠ, AvaⅡ, TaqⅠ, BstNⅠ, Sau 3AⅠ, StuⅠ, BalⅠand SmaⅠwere selected. 2a samples for digestion analysis and validation. RESULTS: Forty NS5b genotyping results showed that 23 cases of type 1b had AluI-specific cleavage sites, no BalⅠ and 2b MboⅠ-cleavage sites, 17 cases of type 2a without AluⅠ and BalⅠ and 2b Mbo I cut point. StuI can be used to diagnose gene mutation in type 1b. Conclusion: The results of HCV NS5b typing suggest that using this typing technique not only achieves the effect of genotyping, but also can detect genetic variation, confirming the existence of mixed infection status of 1b and 1b