Abstract: To investigate the changes of deletion of HPRT exposure to γ ray and benzo-pyrene, and to find a differential diagnosis index for cell injury induced by γ ray and benzo-pyrene human peripheral blood samples from three persons were exposed to ⁶⁰Co γ rays at 10 different doses (0—5 Gy) and benzo-pyrene at 6 different concentrations (0—10 μg/mL), its DNA was isolated from white cell. The changes of deletion of HPRT exposure to γ ray and benzo-pyrene were detected by real time quantitative PCR. The relationship between deletion frequency of HPRT exon and irradiation dose represents certain linear correlation from 0—5 Gy. A linear regression equation has been obtained using statistics regression analysis software: exon-2,y=0.360 3+0.110 68x,R²=0.99,p<0.01;exon-5,y=0.429 8+0.082 3x,R²=0.93,p<0.01 while, the relationship between deletion frequency of HPRT and different concentrations (0—10 μg/mL) represents no statistical significance. There is an obvious influence on deletion frequency of exon 5 of HPRT induced by γ ray,while there is no obvious influence on deletion frequency of exon 5 of HPRT induced by benzo-pyrene,which may be a new differential diagnosis index in the future.

Key words: γ ray, benzo-pyrene, deletion frequency, real time quantitative PCR, HPRT