Construction of calibration curve (dose-response) using gamma radiation and metaphase analysis method for biological dosimetery of over exposed individuals

Introduction. Biological dosimetry is one of the most important methods to estimate radiation dose in over exposed individuals. Chromosomal analysis is the common biodosimetry method. Dicentrics score in peripheral blood lymphocytes (PBL) chromosomes at the first mitosis following in vitro growth stimulation for dose estimation. Each laboratory should establish its own dose-response curves. In this study we constructed calibration curve using standard protocol for culture room of Medical Faculty of Baqiyatallah (a.s) University of Medical Sciences. Material and Methods. The whole peripheral bloods from 3 healthy donors were exposed to different doses of gamma ray (0.25-4Gy). Then lymphocytes were isolated and cultured in complete RPMI-1640 medium. 500 mitoses were analyzed for scoring dicentric chromosomes at each radiation dose for every person after standard metaphase preparation and staining slides. Results. Dose-response curve was constructed based on mean of dicentrics per cell at each radiation dose. Frequency of dicentrics apparently has increased linear quadratically with dose. Discussion. in this study we obtained linear quadratic curve. It seems that there is a nearly good consistence between our dose- response curve with similar studies. This calibration curve is valid for dose estimation of low LET radiation over exposed victims.