{"title":"DNA quality and STR success rate in different formalin-fixed tissues.","authors":"Jinpei Zhang, Lu Li, Xue Bai, Zhe Zhang, Li Yuan","doi":"10.1007/s00414-024-03391-0","DOIUrl":null,"url":null,"abstract":"<p><p>Formalin-fixed tissues possess irreplaceable value as a source of DNA for identification, especially when fresh samples are unavailable. Nonetheless, extracting and amplifying DNA from these tissues is challenging, primarily due to formaldehyde-induced cross-linking and nucleic acid fragmentation. In this study, two pre-extraction treatments, gradual dehydration using ethanol and pre-digestion heat treatments, and three DNA extraction methods, the Chelex-100 method, TIANamp FFPE DNA Kit, and ML Ultra-micro DNA extraction kit, were utilized to optimize DNA extraction from different tissues, which were fixed in 4% unbuffered formalin for different durations. The tissues include the heart, liver, spleen, lung, kidney, muscle, and brain. DNA quality was assessed, and quantification was conducted using Spectrophotometer and Quantifiler<sup>®</sup> Trio DNA Quantification Kits, while the GSTAR™ 25 kit was employed for STR detection. The results indicated that the two pre-extraction treatments exhibited no significant effect on the STR success rate. On day 9, allelic dropout was observed in the heart, liver, spleen, lung, and kidney tissues. Furthermore, allelic dropout was observed in muscle and brain at 12 days and 15 days, respectively. In conclusion, the results underscore the feasibility of effectively extracting DNA from formalin-fixed tissues within 9 days for subsequent STR analysis.</p>","PeriodicalId":14071,"journal":{"name":"International Journal of Legal Medicine","volume":" ","pages":""},"PeriodicalIF":2.2000,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Legal Medicine","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1007/s00414-024-03391-0","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MEDICINE, LEGAL","Score":null,"Total":0}
引用次数: 0
Abstract
Formalin-fixed tissues possess irreplaceable value as a source of DNA for identification, especially when fresh samples are unavailable. Nonetheless, extracting and amplifying DNA from these tissues is challenging, primarily due to formaldehyde-induced cross-linking and nucleic acid fragmentation. In this study, two pre-extraction treatments, gradual dehydration using ethanol and pre-digestion heat treatments, and three DNA extraction methods, the Chelex-100 method, TIANamp FFPE DNA Kit, and ML Ultra-micro DNA extraction kit, were utilized to optimize DNA extraction from different tissues, which were fixed in 4% unbuffered formalin for different durations. The tissues include the heart, liver, spleen, lung, kidney, muscle, and brain. DNA quality was assessed, and quantification was conducted using Spectrophotometer and Quantifiler® Trio DNA Quantification Kits, while the GSTAR™ 25 kit was employed for STR detection. The results indicated that the two pre-extraction treatments exhibited no significant effect on the STR success rate. On day 9, allelic dropout was observed in the heart, liver, spleen, lung, and kidney tissues. Furthermore, allelic dropout was observed in muscle and brain at 12 days and 15 days, respectively. In conclusion, the results underscore the feasibility of effectively extracting DNA from formalin-fixed tissues within 9 days for subsequent STR analysis.
期刊介绍:
The International Journal of Legal Medicine aims to improve the scientific resources used in the elucidation of crime and related forensic applications at a high level of evidential proof. The journal offers review articles tracing development in specific areas, with up-to-date analysis; original articles discussing significant recent research results; case reports describing interesting and exceptional examples; population data; letters to the editors; and technical notes, which appear in a section originally created for rapid publication of data in the dynamic field of DNA analysis.