Dunbar Mignon, Murphy Terence M
Department of Plant Biology, University of California, One Shields Avenue, Davis, CA 95616, USA.
J Forensic Sci. 2009 Jan;54(1):108-13. doi: 10.1111/j.1556-4029.2008.00906.x. Epub 2008 Nov 6.
When rope is found at a crime scene, the type of fiber is currently identified through its microscopic characteristics. However, these characteristics may not always unambiguously distinguish some types of rope from others. If rope samples contain cells from the plants of origin, then DNA analysis may prove to be a better way to identify the type of rope obtained from a crime scene. The objective of this project was to develop techniques of DNA analysis that can be used to differentiate between ropes made from Cannabis sativa L. (hemp), Agave sisalana Perrine (sisal), Musa textilis Née (abaca, "Manila hemp"), Linum usitatissimum L. (flax), and Corchorus olitorus L. (jute). The procedures included extracting the DNA from the rope, performing polymerase chain reaction (PCR) using the extracted DNA as a template, and analyzing the DNA products. A primer pair for PCR, chosen from within a chloroplast gene for the large subunit of ribulose bisphosphate carboxylase/oxygenase, was designed to be specific for plant DNA and complementary to the genes from all five plants. The resulting PCR fragments were approximately 771 base pairs long. The PCR fragments, distinguished through base sequence analysis or restriction enzyme analysis, could be used to identify the five different rope types. The procedure provides a useful addition to visual methods of comparing rope samples.
当在犯罪现场发现绳索时，目前是通过其微观特征来识别纤维类型的。然而，这些特征可能并不总能明确地区分某些类型的绳索。如果绳索样本包含来自其来源植物的细胞，那么DNA分析可能被证明是识别从犯罪现场获取的绳索类型的更好方法。本项目的目的是开发可用于区分由大麻（麻类植物）、剑麻、马尼拉麻、亚麻和黄麻制成的绳索的DNA分析技术。程序包括从绳索中提取DNA，以提取的DNA为模板进行聚合酶链反应（PCR），以及分析DNA产物。从用于核酮糖二磷酸羧化酶/加氧酶大亚基的叶绿体基因中选择的一对PCR引物，被设计成对植物DNA具有特异性且与所有五种植物的基因互补。产生的PCR片段长度约为771个碱基对。通过碱基序列分析或限制性酶分析区分的PCR片段，可用于识别这五种不同类型的绳索。该程序为比较绳索样本的视觉方法提供了有用的补充。
