Rapid Identification of Epithelial Cell Types in Forensic Samples Using Intrinsic Fluorescence and Morphological Signatures

Abstract

Establishing the tissue source of epithelial cells within a biological sample is an important capability for forensic laboratories. In this study we used Imaging Flow Cytometry (IFC) to analyze individual cells recovered from buccal, contact epithelial, and vaginal samples that had been dried between 24 hours and more than eight weeks. Measurements capturing the size, shape, and fluorescent properties of cells were collected in an automated manner and then used to build a multivariate statistical framework for differentiating cells based on tissue type. Results showed that cell populations from the three tissue types could be differentiated using a Discriminant Function plot of IFC measurements. Epidermal cells were distinguished from vaginal and buccal cells with an average classification accuracy of ~94%. Ultimately, cellular measurements such as these, which can be obtained non-destructively, may provide probative information for many types of biological samples and complement results from standard genetic profiling techniques.