en Radiation Biology Radiation Biology تحقيق بديع Original Research <p><strong>Background:</strong> A new biological dosimeter based on methemoglobin level was developed in this study. <strong>Materials and Methods:</strong> Methemoglobin level in erythrocytes from mice subjected to &gamma rays from a ⁶⁰Co source was detected using the methemoglobin kit. The dose range was from 0.5 to 8 Gy and the dose rate was 0.5 Gy/min. <strong>Results:</strong> The results demonstrate that methemoglobin level increases with increasing dose. The detection limit based on methemoglobin has a lower limit of dose estimation of about 1 Gy. The high levels of methemoglobin are maintained for at least 28 days, and the maximal increase of methemoglobin observed occurs at about 30 min after &gamma irradiation. The relationship between dosage and the increased methemoglobin level can be expressed by a linear quadratic equation of y = -8.75 x2 + 168.09 x + 32.66, with the correlation coefficient, r, equal to 0.96. The best suggested time for blood collection is up to 1 day after &gamma irradiation. The doses absorbed by mice as estimated from the use of the dose-response relationship were close to the blind doses of 1, 2, 4 and 8 Gy. <strong>Conclusion:</strong> Methemoglobin is a quick, simple, and precise biomarker for the early assessment of the absorbed dose in mice.</p> : Biological dosimetry, methemoglobin, gamma irradiation, mouse 235 241 http://ijrr.com/browse.php?a_code=A-10-1-567&slc_lang=en&sid=1 X.H. Zhang 790031947532846009819 790031947532846009819 No Department of Nuclear Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, Jiangsu, P.R. China Y.N. Zhang 790031947532846009820 790031947532846009820 No Department of Nuclear Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, Jiangsu, P.R. China X.Y. Min 790031947532846009821 790031947532846009821 No Department of Nuclear Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, Jiangsu, P.R. China Z.C. Lou 790031947532846009822 790031947532846009822 No Department of Nuclear Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, Jiangsu, P.R. China A.L. Wang 790031947532846009823 790031947532846009823 No The First Affiliated Hospital of Bengbu Medical College, Bengbu Medical College, Bengbu, Anhui, P.R. China X.D. Hu 790031947532846009824 790031947532846009824 No Department of Nuclear Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, Jiangsu, P.R. China H.Q. Zhang zhanghq@nuaa.edu.cn 790031947532846009825 790031947532846009825 Yes Department of Nuclear Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, Jiangsu, P.R. China