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Published on: March 9, 2015
Characterization of human DNA in environmental samples
Mary H Toothman1, Karen M Kester, Jarrod Champagne
1Department of Biology, Virginia Commonwealth University, 1000 W. Cary Street, Richmond, VA 23284-2012, USA.
Forensic Science International
|April 19, 2008
Summary
Indoor dust contains significant amplifiable human DNA, posing a contamination risk in forensic investigations. This study quantifies human DNA in dust, highlighting its potential as a forensic evidence source.
Area of Science:
- Forensic Science
- Environmental Science
- Molecular Biology
Background:
- Indoor dust is primarily human skin cells and contains substantial DNA.
- Previous research indicates human DNA presence in dust, but quantities and amplifiability vary.
- Understanding DNA content in dust is crucial for forensic and environmental applications.
Purpose of the Study:
- To quantify amplifiable human DNA in indoor dust samples.
- To correlate DNA quantity with human traffic intensity and visible dust levels.
- To assess the implications of human DNA in dust for forensic investigations and inhabitant identification.
Main Methods:
- Surface swabbing of 576 cm(2) areas in eight indoor locations.
- Analysis of total DNA, human mitochondrial and nuclear DNA using conventional and quantitative PCR.
- Short Tandem Repeat (STR) analysis to assess DNA quality and complexity.
Main Results:
- Human DNA ranged from 0.2-1.1 pg/cm(2) in dust samples.
- Human DNA was detected in 97% of samples.
- 61% of samples yielded complex allele distributions in STR analysis.
Conclusions:
- Indoor dust is a significant source of human DNA, potentially contaminating forensic evidence.
- Strict collection and analysis protocols are necessary to manage dust as a contamination source.
- Dust may serve as a valuable source for identifying indoor inhabitants, pending further research on sample pretreatment and genotype deconvolution.
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