Impact of Donor Age, Gender and Handling Time on the DNA Concentration Left on Different Surfaces

Abstract

Background: We analyzed the correlation between several factors (donor age and gender, and handling time) and trace DNA concentration that participants left on different surfaces (paper, plastic, plastic coated metal) while holding items in their hands or rubbing them with their fingers, their palms, and the side of the palm of the dominant hand. Material and Methods: Sixty participants took part in the study. Items were swabbed with a moistened cotton swab. DNA was isolated using the Chelex procedure and quantified by real-time PCR. Results: We found that DNA concentration transferred to an item was independent of the handling time. On the contrary, it was dependent on the item’s texture; the greatest concentration was left on plastic coated metal (PCM) and the least on paper. The greatest concentration of trace DNA was left by participants from 35 to 44 years of age. Results of the study showed that men deposit a higher DNA concentration than do women. Conclusion: Item texture, donor age, and gender influence trace DNA concentration. Further investigations are necessary to fully understand the process of DNA transfer from donors to handled items.

Keywords

• forensic analysis;
• trace DNA;
• DNA transfer;
• shedding