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DNA Profiling of Complex Biological Mixtures using HLA-Antibody Probes and Fluorescence Activated Cell Sorting

NCJ Number
Date Published
July 2018
73 pages
Outcomes and methodology are reported for a project whose goal was to develop a new analytical technique that uses the intrinsic immunological variation among individuals to separate cells from different sources prior to DNA profiling.

This was attempted with the use of fluorescent antibody probes that target two protein classes of epithelial cells, Human Leukocyte Antigens (HLA) and Cytokeratins (CK). In addition, the researchers characterized variations in intrinsic fluorescence, specifically at red wavelengths (650-670nm), as a potential signature for distinguishing contributor cell populations. Results from HLA hybridization experiments showed the surface antigens on cells transferred from the palmar surface onto a substrate are largely unreactive. Cells showed greater interaction with CK probes, but researchers did not observe consistent differences across contributor cell populations. Flow cytometry analysis showed distinct variation in red autofluorescence profiles between some contributor cell populations. Overall, project results show that separation of contributor cell populations based on intrinsic attributes of epidermal is possible and may possibly be used in conjunction with standard DNA case-working protocols in decreasing the complexity/ambiguity of mixed STR profiles. This introduces a new analytical method that can assist in reducing the bottlenecks, inconclusive results, and loss of evidence that often accompany mixed STR profile interpretation. 16 figures, 3 tables, and a 59-item bibliography

Date Published: July 1, 2018