With the method of PCR-SSCP combined sequencing,we analysed the mutations in the RB1 gene of 10 retinoblastoma samples. All 27 exons of RB1 gene have been examined. The PCR products were digested with some restriction endonuclease to the size of about 200 bp and then denatured into single strands. Loading the single strands of DNA into the 6% polyacrilamide gel,we followed the technology named SSCP to f/nd the abnormal bands in the SSCP gel. After that, the samples found with the abnormal bands in the SSCP gel were amplified again and sequenced to confirm the types and locations of the mutations in the RB1 gene. We have fonnd some kinds of mutations in the RB1 gene.
（Chin J Ocul Fundus Dis,1994,10:17-20）
