Scoring rings in the cell fusion-induced premature chromosome condensation (PCC) assay for high dose radiation exposure estimation after gamma-ray exposure

Abstract

Purpose: This study aimed to construct a calibration curve for high-dose exposure using cell fusion-induced premature chromosome condensation (PCC). Some of the associated practicalities and methodological details were also investigated.Materials and methods: Peripheral blood from two donors was used. PCC mediated by fusing mitotic CHO cells with interphase lymphocytes was carried out. Lymphocytes were irradiated with 60Co (0–20 Gy) and held at 37 °C for 24 h post exposure.Results: The protocol for PCC induction was effective at all doses and the number of rings increased with increasing dose. No significant difference was found between the donors (p = .896) and data were pooled. Ring aberration frequencies followed a Poisson distribution and the dose-response relationship favored a linear fitting: Y = 0.0007(±0.0004)+0.0186(±0.001)×D. Blind tests showed that the estimated doses were all within the 95% confidence limits of the delivered doses. This study has shown that it is valid to score only 100 cells per sample in a triage mode for doses above 5 Gy and that it is valid to score only hollow rings to reduce the scoring time.Conclusion: Scoring rings in cell fusion-induced PCC assay can be a feasible and fast approach for the analysis of high-dose exposures.