Division of Toxicology, Institute for Medical Research and Occupational Health, Zagreb, Croatia.
Teaching Institute of Public Health Brod-Posavina County, Slavonski Brod, Croatia.
Arch Toxicol. 2024 Oct;98(10):3467-3476. doi: 10.1007/s00204-024-03823-1. Epub 2024 Jul 14.
The use of the comet assay in large biomonitoring studies may present logistical and technical challenges because of the processing of numerous samples. Proper sample preservation becomes imperative to prevent spurious DNA breakage. Previous research has shown the feasibility of conducting the comet assay on frozen blood samples, highlighting the potential of freezing at - 80 °C in preserving DNA integrity. Nonetheless, this approach presents challenges, including potential DNA damage during freezing and thawing, variability in processing, and the need for standardized protocols. Our objective was to evaluate whether there are comparable results in DNA migration assessed by the comet assay between fresh and frozen blood samples on a larger scale (N = 373). In our findings, elevated DNA migration was evident in frozen samples relative to fresh ones. Additionally, smoking, alcohol consumption, and season were linked to increased DNA damage levels in whole blood cells. Based on our results and available literature, conducting the comet assay on frozen blood samples emerges as a practical and efficient approach for biomonitoring and epidemiological research. This method enables the assessment of DNA damage in large populations over time, with samples, if properly cryopreserved, that may be used for years, possibly even decades. These observations hold significant implications for large-scale human biomonitoring and long-term epidemiological studies, particularly when samples are collected during fieldwork or obtained from biobanks. Continued method optimization and validation efforts are essential to enhance the utility of this approach in environmental and occupational health studies, emphasizing caution when comparing data obtained between fresh and frozen blood samples.
在大型生物监测研究中使用彗星试验可能会存在一些后勤和技术上的挑战，因为需要处理大量的样本。为了防止虚假的 DNA 断裂，适当的样本保存变得至关重要。先前的研究表明，在冷冻血液样本上进行彗星试验是可行的，这突出了在 -80°C 下冷冻保存 DNA 完整性的潜力。然而，这种方法存在一些挑战，包括在冷冻和解冻过程中潜在的 DNA 损伤、处理过程中的变异性以及对标准化方案的需求。我们的目的是评估在更大规模（N=373）上，新鲜和冷冻血液样本的彗星试验评估的 DNA 迁移是否具有可比的结果。在我们的研究结果中，冷冻样本的 DNA 迁移明显高于新鲜样本。此外，吸烟、饮酒和季节与全血细胞中的 DNA 损伤水平增加有关。根据我们的结果和现有文献，在冷冻血液样本上进行彗星试验是生物监测和流行病学研究的一种实用且高效的方法。这种方法能够随着时间的推移评估大人群中的 DNA 损伤，如果样本得到适当的冷冻保存，可能会使用多年，甚至可能使用几十年。这些观察结果对大规模的人类生物监测和长期流行病学研究具有重要意义，特别是当在实地工作中收集样本或从生物库中获得样本时。持续的方法优化和验证工作对于增强这种方法在环境和职业健康研究中的效用至关重要，同时在比较新鲜和冷冻血液样本之间获得的数据时需要谨慎。
