A simple and fast method was established to identify the sex types of the rat-derived cell strains. The single copy X-chromosome-linked gene AR and the single copy Y-chromosome-linked gene Sry were both detected with qPCR for the rat genomic DNA sample and the AR/Sry ratio was calculated. According to the law of the AR/Sry ratio, a new method to identify the sex types of the rat-derived cell strains was developed. The new assay was proved effective. The new assay showed advantages over the traditional sex type identification PCR methods, which detected only the Sry gene. Moreover, the new method was used to identify the sex types of two rat-derived cell strains unknown for the sex types and the results were confirmed with the in situ hybridization. Finally, the problem of the cross contamination between the female and the male samples was addressed and discussed extensively.
Keywords: AR/Sry ratio; X-chromosome-linked gene; Y-chromosome-linked gene; quantitative PCR analysis (qPCR); sex type identification.