Self- and non-self-DNA on hands and sleeve cuffs

Area of Science:

• Forensic genetics
• Human DNA analysis
• Trace evidence

Background:

• Modern DNA detection methods offer high sensitivity for forensic analysis.
• Understanding background DNA transfer is crucial for interpreting forensic evidence.
• Sleeve cuffs are understudied as potential DNA transfer intermediates.

Purpose of the Study:

• To analyze DNA composition on sleeve cuffs and hands over a working day.
• To investigate factors influencing DNA shedding and transfer.
• To assess the role of clothing in secondary DNA transfer.

Main Methods:

• Sampling DNA from participants' hands and sleeve cuffs over 25 working days.
• Monitoring DNA shedding capacity and non-self-DNA presence.
• Comparing DNA yields from different fabric types (synthetic, cotton, leather).

Main Results:

• Non-self-alleles were detected in 95% of samples.
• Sleeve cuffs yielded more DNA than hands, with synthetic cuffs being most effective.
• DNA shedding varied significantly during the day, and family DNA diminished while colleague DNA increased.
• Unknown major DNA profiles, suitable for database entry, were found on cuffs and hands.

Conclusions:

• Sleeve cuffs are important DNA transfer vectors, collecting more environmental DNA than hands.
• Individual DNA shedding is dynamic and influenced by daily activities and environment.
• Clothing, particularly synthetic materials, can significantly contribute to secondary DNA transfer in forensic investigations.