The role of flow cytometry in forensic investigation: a review

Flow cytometry is a laser-based technique that analyses single cells or particles suspended in a buffered salt-based solution. It has applications in multiple areas, including cancer biology, molecular biology, virology, immunology, and infectious disease monitoring. In forensic investigations, flow cytometry has been employed to analyse a variety of samples. Flow cytometry has indeed found significant applications in forensic science, particularly in determining the post-mortem interval (PMI), investigating sexual assault cases and analyzing ‘touch DNA’ for identifying perpetrators. This review is an overview of how flow cytometry has been utilized in these areas, based on studies from 1999 to 2021. Articles were retrieved using academic search systems such as Google Scholar, PubMed, MEDLINE, Scopus, and Science Direct, using keywords such as flow cytometry, forensic pathology, forensic medicine, sexual assault, touch DNA, post-mortem interval, PMI, and forensic science. A total of 86 publications were assessed, of which 52 met our criteria. Many studies have explored the use of flow cytometry for PMI estimation and perpetrator identification in sexual assault cases. Flow cytometry is particularly beneficial for accurate and non-destructive assessment of touch DNA samples that are processed simultaneously with routine casework procedures for DNA analysis. Flow cytometry is useful in forensic pathology when other techniques fail, because it detects various common genetic abnormalities in dead cells and tissues. In summary, flow cytometry is a superior alternative to other methods because it offers rapid analysis, high sensitivity, and ease of use. These benefits make it an invaluable tool in research and clinical settings, providing efficient and accurate cell analysis that can significantly enhance both diagnostic and therapeutic processes.