Ozcagli Eren, Yesilcimen Esma Soylemez, Omurtag Gulden Zehra
Istanbul University, Faculty of Pharmacy, Department of Pharmaceutical Toxicology, 34116, Istanbul, Turkey.
Istanbul Medipol University, School of Pharmacy, Department of Pharmaceutical Toxicology, 34815, Istanbul, Turkey; Istanbul Pendik Veterinary Control Institute, Department of Pharmacology, 34890, Istanbul, Türkiye.
Mutat Res Genet Toxicol Environ Mutagen. 2025 Feb-Mar;902:503851. doi: 10.1016/j.mrgentox.2025.503851. Epub 2025 Jan 26.
The comet assay is a rapid, simple and sensitive method for the detection of DNA damage and repair at the level of individual cells, with a wide range of applications in human biomonitoring and molecular epidemiology. It is common practice to perform the comet assay on fresh samples to preserve the integrity of the DNA and to obtain reliable results, which is why most published studies have been designed using fresh blood samples. There are limitations associated with the use of fresh samples for this assay and the need for appropriate storage for some studies. The aim of this study was to determine changes in DNA damage and DNA repair kinetics during medium- and long-term storage of human whole blood (WB) samples without adding cryopreservatives. Whole blood samples were divided into small portions and tested after overnight storage at + 4 °C. Frozen samples were stored at -20 and -80 °C for 3 different time points: 30, 90 and 180 days. Frozen samples were compared with fresh samples stored at + 4 °C in terms of DNA damage and repair. For WB samples stored at -80 °C, showed an increase in purine base damage (PBD) and DNA repair alterations were determined while no increase in basal DNA damage was observed. According to the results of our study, storage of WB samples for comet assay in small portions at -20 °C for up to 90 days does not cause any additional damage and does not cause any alter DNA repair kinetics.
彗星试验是一种快速、简单且灵敏的方法，用于在单个细胞水平检测DNA损伤和修复，在人类生物监测和分子流行病学中有广泛应用。对新鲜样本进行彗星试验以保持DNA完整性并获得可靠结果是常见做法，这就是为什么大多数已发表的研究都采用新鲜血液样本进行设计。使用新鲜样本进行该试验存在局限性，且某些研究需要适当储存。本研究的目的是确定在不添加冷冻保护剂的情况下，人类全血（WB）样本中长期储存期间DNA损伤和DNA修复动力学的变化。全血样本分成小份，在 +4°C过夜储存后进行检测。冷冻样本在 -20°C和 -80°C储存3个不同时间点：30天、90天和180天。将冷冻样本与储存在 +4°C的新鲜样本在DNA损伤和修复方面进行比较。对于储存在 -80°C的WB样本，嘌呤碱基损伤（PBD）增加，且确定了DNA修复改变，而未观察到基础DNA损伤增加。根据我们的研究结果，将用于彗星试验的WB样本小份在 -20°C储存长达90天不会造成任何额外损伤，也不会改变DNA修复动力学。
