Abstract: This report describes a method to separate mRNAs by means of the Polymerase Chain Reaction(Differential Display mRNA) , and identifies the genes related to lung cancer induced by radiation by this method.The RNAs were isolated f rom two pairs of sample , SV40 - immortalized human fetal t racheal fibroblast cell (SHTF) versusαSHTF cell (SHTF cell irradiated byαparticle) , and lung cancer tissue versus normal lung tissue obtained f rom one patient . These RNAs were amplified by RTPCR. The differential expressed gene fragment s were display by autoradiograph or silver nit rate stain. The result showed that the differential display mRNA were established on both cell and tissue samples. The bands stained by silver nit rate is more clear than the bands on X2ray film. The rate of reamplification of differential expressed genes f ragment s stained by silver nit rate is 80 % , higher than autoradiograph , 50 %.

Key words: Differential Display mRNA, Autoradiograph, Silver nit rate stain, Cancer induced by irradiation