Classification of epidermal, buccal, penile and vaginal epithelial cells using morphological characteristics measured by imaging flow cytometry

• Published in: Forensic science international 2024-12, Vol.365, p.112274, Article 112274
• Main Authors: Ross, Dana, Taylor, Duncan, van Oorschot, Roland A.H., Best, Giles, Goray, Mariya
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Biological effects; Cell identification; Cell morphology; Cells; Classification; Conditional probability; Discriminant Analysis; DNA; Epidermal Cells - cytology; Epithelial cells; Epithelial Cells - cytology; Epithelium; Ethnicity; Female; females; Flow Cytometry; Forensic science; forensic sciences; Hands; Humans; Identification; Imaging flow cytometry; Male; males; Middle Aged; Morphology; Mouth Mucosa - cytology; Penis; Penis - cytology; Physical characteristics; probability; Software; Statistical analysis; Vagina; Vagina - cytology; Young Adult
• ISSN: 0379-0738; 1872-6283; 1872-6283
• DOI: 10.1016/j.forsciint.2024.112274

As a result of the increased sensitivity of forensic DNA techniques, which can generate informative results from as little as a few cells, developing an understanding of the anatomical region these cells originate from is becoming more pertinent. Imaging Flow Cytometry (IFC) represents a promising method for identifying epithelial cells from different anatomical regions. This project aimed to determine whether IFC could be used to distinguish epithelial cells collected from different forensically relevant anatomical regions based on their morphology and autofluorescence. Penile, vaginal, buccal, and epidermal epithelial cells were collected in triplicate from 15 male and 15 female participants, in three different age groups: 18–39, 40–59, and 60+ years. Using the high statistical output from the IFC, 234 morphological measurements were collected for 571,546 single cells. Using a linear discriminate analysis with a minimum posterior probability threshold, the four epithelial cell types could be identified and distinguished with a 72–83 % classification accuracy. The results showed that the age and biological sex of the individual had no effect on the morphology of the four epithelial cell types. These data provide insights into the ability of IFC to identify and distinguish penile, buccal, vaginal, and epidermal epithelial cells and identifies further avenues for improvement and optimisation. •LDA differentiated four epithelial cells with 83 % accuracy.•90 % classification accuracy can be achieved with use of classification thresholds.•Age of an individual does not appear to influence cell morphology.•Sex of an individual also does not appear to influence cell morphology.•Samples from the same individual taken within a week showed higher association.