This optimized protocol (including links to instruction videos) describes a comet-based in vitro DNA repair assay that is relatively simple, versatile, and inexpensive, enabling the detection of base and nucleotide excision repair activity. Protein extracts from samples are incubated with agarose-embedded substrate nucleoids (‘naked’ supercoiled DNA) containing specifically induced DNA lesions (e.g., resulting from oxidation, UVC radiation or benzo[a]pyrene-diol epoxide treatment). DNA incisions produced during the incubation reaction are quantified as strand breaks after electrophoresis, reflecting the extract’s incision activity. The method has been applied in cell culture model systems, human biomonitoring and clinical investigations, and animal studies, using isolated blood cells and various solid tissues. Once extracts and substrates are prepared, the assay can be completed within 2 d.

这个优化的协议（包括指导视频的链接）描述了一种基于彗星的体外 DNA 修复试验，该试验相对简单、通用且价格低廉，能够检测碱基和核苷酸切除修复活性。将样品的蛋白质提取物与含有特异性诱导的 DNA 损伤（例如，由氧化、UVC 辐射或苯并[a]芘-二醇环氧化物处理产生）的琼脂糖包埋底物类核（“裸”超螺旋 DNA）一起孵育。孵育反应期间产生的 DNA 切口在电泳后被量化为链断裂，反映了提取物的切口活性。该方法已应用于细胞培养模型系统、人体生物监测和临床研究以及动物研究，使用分离的血细胞和各种实体组织。