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Development of 18S rRNA gene arrays for forensic detection of diatoms
- Source :
- Forensic Science International. 317:110482
- Publication Year :
- 2020
- Publisher :
- Elsevier BV, 2020.
-
Abstract
- Diatom test is the most commonly used method to diagnose drowning in forensic laboratories. However, microscopic examination and identification of diatom frustules is time-consuming and requires taxonomic expertise. At present, the identification of drowning is still a challenge in forensic casework. In this study, we developed a novel diatom microarray based on the detection of specific 18S rRNA gene fragments of diatom species. The array covers 169 diatom species which were documented as commonly found in a wide range of fresh waters in China. Diatom arrays were prepared from species specific oligonucleotide probes targeting to variable regions of the 18S rRNA gene. We also developed an auxiliary sample preparation method for isolation of diatom DNA from tissues, which enabled detection of diatom species in real forensic samples as well as environmental waters. We applied the diatom arrays to analyze six drowned cases and eight environmental samples. The diatom arrays showed much better sensitivity and more consistent results than those of the conventional SEM methods. We discovered major discrepancies between results generated by the diatom arrays and the routinely used SEM based diatom tests. We verified the results of our diatom arrays by species specific PCR and Sanger sequencing and found that the currently used SEM diatom test method has a serious deficiency in sensitivity due to high loss rate of frustules in the sample preparation procedure. We anticipate that the application of diatom arrays will transform current forensic practice of diagnosing drowning deaths.
- Subjects :
- Swine
Polymerase Chain Reaction
01 natural sciences
18S ribosomal RNA
Pathology and Forensic Medicine
03 medical and health sciences
symbols.namesake
0302 clinical medicine
Species Specificity
RNA, Ribosomal, 18S
Animals
Humans
030216 legal & forensic medicine
Lung
Oligonucleotide Array Sequence Analysis
Diatoms
Sanger sequencing
Drowning
biology
fungi
010401 analytical chemistry
Water
Sequence Analysis, DNA
Forensic Medicine
biology.organism_classification
0104 chemical sciences
Diatom
Evolutionary biology
symbols
Oligonucleotide Probes
Law
Loss rate
Subjects
Details
- ISSN :
- 03790738
- Volume :
- 317
- Database :
- OpenAIRE
- Journal :
- Forensic Science International
- Accession number :
- edsair.doi.dedup.....f9c9c07ff9695b37d88f462e9d73c6fe