6-Thioguanine resistant T-lymphocyte determination as a possible indicator of human ionizing radiation exposure

We used the autoradiographic assay to assess human in vivo somatic cell gene mutation at the hypoxanthine guanine phosphoribosyl transferase (hgprt) locus in T-lymphocytes. Cells able to incorporate tritiated thymidine in vitro in 6-thioguanine containing shot-term cultures were enumerated in order to determine 6-thioguanine resistant (TGr) variant frequencies in cryopreserved lymphocytes from control indivuals and 3 persons suspected of 60Co exposure from an accident in Cd. Juárez, México. The data indicate that the lymphocyte TGr variant frequency assay may be potencially usefull for human population monitoring following accidental to ionizing radiation