en Radiation Biology Radiation Biology تحقيق بديع Original Research <p><strong>Background: </strong>Lymphocyte-dicentric assay is the most generally accepted method for biological dosimetry of overexposed individuals. In this study, the frequency of unstable chromosome <br>aberration in blood lymphocytes was used to estimate radiation dose received by individuals. Evaluation of dose using a calibration curve produced elsewhere may have a significant uncertainty therefore, experiments were performed to produce a dose-response curve using an <br>established protocol of international atomic energy agency. </p><p><strong>Materials and Methods: </strong>Lymphocytes in whole peripheral blood obtained from healthy <br>individuals, were exposed to various doses of gamma radiation (0.25 – 4 Gy). Then after 1 hour of incubation in 37 ^oC, were cultured in complete RPMI-1640 medium. 500 mitoses were <br>analysed for the presence or absence of unstable chromosomal aberrations for each radiation dose after the standard metaphase preparation and staining slides. </p><p><strong>Results and Conclusion: </strong>Intercellular distribution of dicentric chromosomes at each radiation dose has been used to contrast a dose-response curve. It seems that dose-effect relationship <br>follows with the linear-quadratic model. There is a good agreement between our dose-response curves with similar published studies by other laboratories. <i>Iran </i><i>. J. Radiat. Res., 2004 2 (2): 85-8 </i><i>8 </i></p> ,Biological dosimetry,calibration curve,dicentric chromosome,human lymphocytes 85 88 http://ijrr.com/browse.php?a_code=A-10-1-63&slc_lang=en&sid=1 S.A. Haeri haeri80@yahoo.com 79003194753284600152 79003194753284600152 Yes H. Mozdarani 79003194753284600153 79003194753284600153 No M. Foroghizadeh 79003194753284600154 79003194753284600154 No A. Mahmoudzadeh 79003194753284600155 79003194753284600155 No