【摘要】 用巢式PCR－RFLP分析技术，扩增大便中K－ras基因第12位密码子所处的一段外显子，根据BstNI内切酶的多态性，分析K－ras基因第12位密码子是否突变。结果在22例结肠直肠癌患者的术后石蜡包埋组织中，检出10例（45.5％）K－ras突变，该10例患者中，有8例（36．4％）患者的术前大便中检出K－ras基因突变。这种方法快速、简便、特异、敏感，且可避免大便中多种物质对PCR的干扰。对可疑人群具有实际应用价值。更多还原

【Abstract】 A fragment of extron at codon 12 of K-ras gene in feces was amplified bynested PCR-RFLP and degisted with restriction enzpoe Bst NI.K-ras gene mutations weredetected out in the pathological tissues of 10 of 22 patients with co1onic and rectal cancers after operation.However,the mutations were detected out in the feces specimens from 8 of the22 patients before operation.The method was rapid,simple,specific,sensitive and not interfered with other materials in feces.It could be app1ied for the screening of doubtful patientswith colonic and rectal cancers.更多还原