Institute of Legal Medicine, Prittwitzstrasse 6, Ulm, Germany.
Int J Legal Med. 2011 Sep;125(5):727-31. doi: 10.1007/s00414-010-0424-x. Epub 2010 Mar 2.
Highly sensitive short tandem repeat-based stain analysis of weak biological stains has been improved during the last years. The risk of transfer of cellular material from handled items contaminated with biological stains such as blood and saliva is of forensic relevance. Although the policemen working with crime scene items are very careful, there exists a potential risk of transfer contamination. To obtain estimates for the risk of stain transfer by handling, we have carried out an experimental study on 288 dried blood and saliva stains in two laboratories. DNA quantification showed only small amounts of DNA that could be transferred, especially from stains on paper and cotton. The saliva and especially the blood stains from plastic surface resulted in higher amounts of transferred DNA, depending on the relation of blood volume to included area: Of 192 direct transfers, 17% gave extracts above 10 pg DNA/μl, and only 3% of 96 secondary transfers resulted in amounts above 10 pg DNA/μl.
近年来，基于短串联重复序列的高度敏感染色分析技术得到了改进。处理被血液和唾液等生物污渍污染的物品时，细胞物质转移的风险具有法医学相关性。尽管处理犯罪现场物品的警察非常小心，但仍然存在转移污染的潜在风险。为了评估通过处理操作导致污渍转移的风险，我们在两个实验室中对 288 个干燥的血液和唾液污渍进行了一项实验研究。DNA 定量显示，只有少量的 DNA 可以转移，尤其是来自纸张和棉花上的污渍。来自塑料表面的唾液，特别是血迹，会导致更多的转移 DNA，这取决于血液量与包含面积的关系：在 192 次直接转移中，有 17%的提取液中 DNA 含量超过 10 pg/μl，而在 96 次二次转移中，只有 3%的提取液中 DNA 含量超过 10 pg/μl。
