Foster Nicole R, Martin Belinda, Hoogewerff Jurian, Aberle Michael G, de Caritat Patrice, Roffey Paul, Edwards Robert, Malik Arif, Thwaites Priscilla, Waycott Michelle, Young Jennifer
College of Science and Engineering, Flinders University, GPO Box 2100, Adelaide, South Australia 5001, Australia.
College of Science and Engineering, Flinders University, GPO Box 2100, Adelaide, South Australia 5001, Australia.
Forensic Sci Int. 2023 Mar;344:111599. doi: 10.1016/j.forsciint.2023.111599. Epub 2023 Feb 7.
Environmental DNA (eDNA), elemental and mineralogical analyses of soil have been shown to be specific to their source material, prompting consideration of using the airborne fraction of soil (dust) for forensic intelligence work. Dust is ubiquitous in the environment and is easily transferred to items belonging to a person of interest, making dust analysis an ideal tool in forensic casework. The advent of Massive Parallel Sequencing technologies means metabarcoding of eDNA can uncover bacterial, fungal, and even plant genetic fingerprints in dust particles. Combining this with elemental and mineralogical compositions offers multiple, complementary lines of evidence for tracing the origin of an unknown dust sample. This is particularly pertinent when recovering dust from a person of interest to ascertain where they may have travelled. Prior to proposing dust as a forensic trace material, however, the optimum sampling protocols and detection limits need to be established to place parameters around its utility in this context. We tested several approaches to collecting dust from different materials and determined the lowest quantity of dust that could be analysed for eDNA, elemental composition and mineralogy, whilst still yielding results capable of distinguishing between sites. We found that fungal eDNA profiles could be obtained from multiple sample types and that tape lifts were the optimum collection method for discriminating between sites. We successfully recovered both fungal and bacterial eDNA profiles down to 3 mg of dust (the lowest tested quantity) and recovered elemental and mineralogical compositions for all tested sample quantities. We show that dust can be reliably recovered from different sample types, using different sampling techniques, and that fungi and bacteria, as well as elemental and mineralogical profiles, can be generated from small sample quantities, highlighting the utility of dust for forensic intelligence.
环境DNA（eDNA）、土壤的元素和矿物学分析已被证明对其源材料具有特异性，这促使人们考虑将土壤的空气传播部分（灰尘）用于法医情报工作。灰尘在环境中无处不在，很容易转移到与感兴趣的人相关的物品上，这使得灰尘分析成为法医案件工作中的理想工具。大规模平行测序技术的出现意味着eDNA的宏条形码分析可以揭示灰尘颗粒中的细菌、真菌甚至植物遗传指纹。将此与元素和矿物组成相结合，可为追踪未知灰尘样本的来源提供多条互补的证据线索。当从感兴趣的人身上采集灰尘以确定他们可能去过的地方时，这一点尤为相关。然而，在将灰尘提议作为法医痕迹材料之前，需要建立最佳采样方案和检测限，以便在此背景下确定其效用的参数。我们测试了几种从不同材料收集灰尘的方法，并确定了可用于分析eDNA、元素组成和矿物学的最低灰尘量，同时仍能得出能够区分不同地点的结果。我们发现可以从多种样本类型中获得真菌eDNA谱，并且胶带粘贴是区分不同地点的最佳收集方法。我们成功地从低至3毫克的灰尘（测试的最低量）中恢复了真菌和细菌eDNA谱，并对所有测试样本量恢复了元素和矿物组成。我们表明，可以使用不同的采样技术从不同样本类型中可靠地收集灰尘，并且可以从小样本量中生成真菌、细菌以及元素和矿物学谱，突出了灰尘在法医情报中的效用。
