Pan centromeric FISH enhances precision in radiation biodosimetry.

Accurate biodosimetry is critical for assessing radiation exposure in radiological emergencies, occupational monitoring, and clinical management, where precise dose estimation informs life-saving decisions and regulatory compliance. Current gold-standard cytogenetic methods face limitations in sensitivity and reproducibility, especially at low doses (< 0.5 Gy) (practical limitations at low doses, including very low dicentric yields, higher statistical noise, and greater scoring uncertainty as aberration frequencies near background levels). This study presents a systematic comparison of pan-centromeric fluorescence in situ hybridization (pan-cent-FISH) and Giemsa staining for detecting dicentric (DC) and ring (R) chromosomes following 60Co-γ irradiation (0–3 Gy). Analysis of more than 15,000 metaphases per technique revealed enhanced sensitivity of pan-cent-FISH technique, demonstrating a 1.72-fold higher linear coefficient and enhanced (1.13-fold) quadratic coefficient (β), indicating improved sensitivity across both low and high dose ranges. Blind validation with eight samples showed pan-cent-FISH achieved ~ 2-fold greater accuracy, with mean absolute differences of 0.0538 Gy (vs. 0.1105 Gy for Giemsa) and average relative errors of 7.13% (vs. 15.35% for Giemsa). At low doses (0.1 Gy), pan-cent-FISH maintained 9.0% error, while Giemsa exceeded acceptable limits (21.0% error). The standardized fluorescence detection used for the technique eliminated morphological ambiguities, reducing false negatives by ~ 40% and improving first-pass accuracy.