Detection of cellular material in lip-prints

Area of Science:

• Forensic Science
• Cell Biology
• Dermatology

Background:

• Cellular material transfer from lips occurs via food, drinks, or during sexual contact.
• Existing methods can detect touch-induced cellular material.
• Lip prints represent a potential source of biological evidence.

Purpose of the Study:

• To investigate the visualization of cellular material in lip prints using Diamond™ dye (DD).
• To determine the consistency and variability of cell shedding within lip prints among individuals.
• To explore potential correlations between lip shedding, morphology, and other factors.

Main Methods:

• Ten volunteers provided lip prints on glass slides after a 30-minute fasting period.
• Lip prints were created with medium pressure for 15 seconds, with five replicates per individual.
• Cellular material visualization was performed using Diamond™ dye (DD).

Main Results:

• Consistent 'lip shedder' status (heavy to light) was observed for each individual.
• Females generally shed more cells than males.
• No correlation was found between lip shedder status and thumb print cell deposition or lip morphology. Lip balm did not affect visualization, while lipstick did.

Conclusions:

• Diamond™ dye (DD) effectively visualizes cellular material in lip prints.
• Lip prints provide a consistent source of cellular material for forensic identification.
• This technique allows for targeted DNA collection from lip prints, extending beyond finger-based evidence.