Department of Forensic Science, Virginia Commonwealth University, Richmond, VA, USA.
J Forensic Sci. 2021 Jul;66(4):1427-1434. doi: 10.1111/1556-4029.14694. Epub 2021 Feb 24.
Sample collection at the crime scene can introduce variations in DNA recovery based upon the substrate from which a sample is collected, the material of the collection device used, or the storage conditions after collection. There are many factors during this process that can degrade the sample during drying and storage, and before DNA extraction can be performed. The purpose of this study was to evaluate and compare the performance of standard cotton swab collection with the Bode BioSafe swab, which includes both a desiccant at the swab head and proprietary compounds to prevent degradation of the sample during sample collection and preservation. Blood and touch DNA samples were collected from porous and nonporous substrates and stored at elevated temperatures to simulate accelerated time. DNA quantification and STR profile data were used to assess the performance of the swabs. BioSafe swab collection resulted in similar DNA yields from blood samples and significantly higher DNA yields from touch samples when compared to collection with cotton swabs. BioSafe swabs also resulted in higher DNA integrity during long-term storage, increased STR profile success and improved retention of low-level contributor alleles.
在犯罪现场采集样本时，由于样本采集的基底、采集装置的材料或采集后的储存条件等因素，可能会导致 DNA 回收出现差异。在干燥和储存过程中，以及在进行 DNA 提取之前，有许多因素会导致样本降解。本研究的目的是评估和比较标准棉签采集与 Bode BioSafe 棉签的性能，后者的棉签头部含有干燥剂，并且含有专有化合物，可以防止样本在采集和保存过程中降解。从多孔和非多孔基质中采集血液和接触 DNA 样本，并将其储存在高温下以模拟加速时间。使用 DNA 定量和 STR 图谱数据来评估棉签的性能。与使用棉签采集相比，BioSafe 棉签采集血液样本的 DNA 产量相似，但采集接触样本的 DNA 产量显著更高。BioSafe 棉签在长期储存过程中也具有更高的 DNA 完整性，提高了 STR 图谱成功率，并保留了低水平供体等位基因。
