Abstract：
DNA degradation in biological material needs to be better understood. Bloodstains on washed clothing are disturbed by washing procedures, sometimes transferred to other fabrics, often with latent bloodstains and usually with significantly degraded DNA. The samples (cotton fabric with bloodstains) are divided into six main groups, depending on the washing method regarding water temperature (95, 60, and 30 °C) and the detergent use. After completing the washing process, samples were stored for a certain period (1 day to 6 months) and subsequently analyzed. Analyses were performed using standard protocols and commercial kits to measure the remaining DNA quantity (concentration) and DNA degradation index in the processed samples. Our results revealed that the high washing temperature (60 and 95 °C) and the application of detergent have a synergic action on DNA degradation, while at 30 °C this effect is absent. Furthermore, the effect of detergent on accelerated DNA degradation is observed about a month after the washing. This delayed effect of detergent has no explanation in current literature data. To obtain optimal results from the bloodstains, we recommended that the period from the crime event and attempted cleaning by a perpetrator to the laboratory analysis should be less than 1 month.
摘要：
需要更好地理解生物材料中的DNA降解。洗过的衣服上的血迹会受到洗涤程序的干扰，有时转移到其他织物上，通常有潜在的血迹，通常有显著降解的DNA。样品(有血迹的棉织物)分为六个主要组，根据水温（95、60和30°C）的洗涤方法和洗涤剂的使用。完成洗涤过程后，样本储存一段时间(1天至6个月),随后进行分析.使用标准方案和商业试剂盒进行分析以测量经处理的样品中的剩余DNA量(浓度)和DNA降解指数。我们的结果表明，高洗涤温度（60和95°C）和洗涤剂的应用对DNA降解具有协同作用，而在30°C时，这种效果是不存在的。此外，在洗涤后约一个月观察到洗涤剂对加速DNA降解的影响。洗涤剂的这种延迟效应在目前的文献数据中没有解释。为了从血迹中获得最佳结果，我们建议从犯罪事件和肇事者试图清洁到实验室分析的时间应少于1个月。
