英语语法分析

Extron 1-5 of RHO gene was amplified by polymerase chain reaction (PCR), and the mutation of RHO gene was screened by direct DNA sequence measurement.

采用聚合酶链反应(PCR)方法扩增rho基因第1 ~ 5外显子和第1内含子基因片段，用直接dna测序法筛查rho基因突变。