METHODS The reverse transcription polymerase chain reaction(RT PCR) was used to detect expression of mdr 1 mRNA in 20 RCC and 5 normal kidneys.

• 方法应用逆转录?聚合酶链反应（RT?PCR）技术检测20例肾癌和5例正常肾组织mdr?1基因mRNA的表达。