Comparative analysis of DNA collection techniques applied to disposable 3-layer earloop face masks

Area of Science:

• Forensic Science
• Molecular Biology
• Genetics

Background:

• The widespread use of face masks during the COVID-19 pandemic presents new opportunities for forensic DNA analysis.
• Face masks worn by individuals can retain biological material, serving as potential evidence at crime scenes.

Purpose of the Study:

• To develop and validate a rapid method for extracting abundant human DNA from disposable face masks.
• To assess the suitability of extracted DNA for short tandem repeat (STR) genotyping.

Main Methods:

• Ten volunteers wore 3-layer disposable face masks for 2 hours.
• DNA was extracted by directly cutting the inner layer of the masks.
• DNA yields were quantified, and STR genotyping was performed on mockup samples.

Main Results:

• The optimal DNA extraction method involved cutting the inner layer of the mask, yielding sufficient DNA for STR analysis.
• DNA concentrations were comparable between male and female donors.
• Even small mask areas (28 cm²) and lower DNA concentrations (0.0083 ng/μL from carbon masks) were adequate for genotyping >19 autosomal STR loci.

Conclusions:

• Disposable face masks are a viable source of forensic DNA evidence.
• The developed rapid extraction method is efficient and effective for obtaining DNA profiles from face masks.
• This technique can significantly aid human identification in forensic investigations.