Lewis grouping of human secretion stains

Area of Science:

• Forensic Science
• Immunogenetics
• Biochemistry

Background:

• The Lewis blood group system is linked to the secretor system, influencing ABH factor presence in secretions.
• Conflicting reports exist regarding Lewis substances in secretions, impacting their use in forensic analysis.
• Lewis typing may verify non-secretor results from ABO typing in forensic investigations.

Purpose of the Study:

• To investigate the utility of Lewis typing in forensic casework.
• To examine the activity and viability of Lewis substances in various human secretion stains.
• To assess the stability of Lewis substances in saliva, vaginal, and semen stains over time.

Main Methods:

• Paired saliva and vaginal stains were collected from laboratory donors.
• Paired saliva and semen stains were collected from laboratory donors.
• Lewis substance activity and stability were analyzed over a ten-week period.

Main Results:

• The study describes the activity of Lewis substances in saliva, vaginal, and semen stains.
• Viability of Lewis substances in these stains over a ten-week period was documented.
• Preliminary data on Lewis substance presence and stability in forensic samples were obtained.

Conclusions:

• Lewis typing of secretion stains shows potential for forensic casework.
• Further investigation is warranted to confirm the reliability of Lewis typing in forensic applications.
• Understanding Lewis substance stability is crucial for interpreting results from dried stains.