Abdel Hady Randa H, Thabet Hayam Z, Ebrahem Noha Esmael, Yassa Heba A
Acad Forensic Pathol. 2021 Mar;11(1):7-23. doi: 10.1177/1925362121998547. Epub 2021 Mar 19.
Forensic investigations using DNA analysis have been grown rapidly. Samples retrieved from crime scene may be exposed to different conditions before proceeding. This study aimed to evaluate the effect of different grades of temperature and burn on DNA extraction and typing.
Seven mL of blood and four mL of semen were collected from each volunteer. Effects of temperature grades (100 °C, 50 °C, 37 °C, 4 °C, -20 °C, and burn) on blood and seminal stain were tested.
Bloodstains exposed to temperature grades 100 °C, 50 °C, 37 °C, 4 °C, and -20 °C can be identified using preliminary test while burnt blood stain cannot. Seminal stains exposed to temperature grades 37 °C, 4 °C, and -20 °C can be identified by Florence test while those exposed to 100 °C, 50 °C, and burn cannot. Blood and seminal stains exposed to temperature grades 100 °C, 50 °C, and burn show marked reduction in DNA concentration while maximum DNA conc could be recovered from stains exposed to temperature grade temperature. Both blood and seminal DNA was affected only in case of burn without significant difference between THO1 and Amelogenin primers.
High environmental temperature affect the quantity of extracted DNA from different stains but less effect on the quality of extracted DNA. Burn affects both preliminary test, DNA quantity, and quality in stains.
使用DNA分析的法医调查发展迅速。从犯罪现场获取的样本在进行分析之前可能会暴露于不同的条件下。本研究旨在评估不同温度等级和灼烧对DNA提取和分型的影响。
从每位志愿者身上采集7毫升血液和4毫升精液。测试了温度等级（100℃、50℃、37℃、4℃、-20℃和灼烧）对血液和精液污渍的影响。
暴露于100℃、50℃、37℃、4℃和-20℃温度等级的血迹可以通过初步测试进行鉴定，而灼烧的血迹则不能。暴露于37℃、4℃和-20℃温度等级的精液污渍可以通过弗洛伦斯试验进行鉴定，而暴露于100℃、50℃和灼烧的精液污渍则不能。暴露于100℃、50℃和灼烧温度等级的血液和精液污渍的DNA浓度显著降低，而从暴露于温度等级的污渍中可以回收最大DNA浓度。只有在灼烧的情况下，血液和精液DNA才会受到影响，THO1和牙釉蛋白引物之间没有显著差异。
高环境温度会影响从不同污渍中提取的DNA数量，但对提取的DNA质量影响较小。灼烧会影响污渍的初步测试、DNA数量和质量。
