Resolving mixtures remains one of the most significant challenges in forensic DNA analysis. The advent of probabilistic genotyping methods have been instrumental in addressing these challenges however these systems use mathematical and statistical modeling to probabilistically deconvolute profiles. Instead, envision a world unburdened by mixed profiles and statistical uncertainty; this is the story of how recent advances in single cell analyses in forensic science have evolved to become a new multifaceted tool to reduce complexity and provide the highest profile resolution possible.

Single cell analysis has long been a focus outside of the forensic community, with innovative instruments and techniques being developed at a rapid pace. However, the forensic DNA field has yet to take full advantage of this powerful analysis. In addition, single cell analyses can offer more than improvements in the resolution of mixtures, meeting other significant needs in the forensic community. For example, the ability to link the DNA profile with cell type and help inform low quantity bulk sample interpretation.

However, it is not without challenges, namely, cell recovery methods suitable for forensic use, throughput, and inherent stochastic effects (i.e., Will enough information be present to make conclusions?). These challenges have been or are currently being addressed. 

This presentation will provide a historical overview of single cell analysis and highlight recent advances including several studies that provide perspective into methods, expected results, advantages/disadvantages and the transition of these analyses from research to the forensic laboratory. These studies include: an overarching view of how modern technologies coupled with slight modifications to the standard workflow can impact profile quality and the information content that can be obtained from single cells; a method to target and recover male epithelial cells from a mixture of female like-cells; the first perspective into the dynamics of stutter on single-copy genomes and the implications on bulk analysis; and preliminary data related to single cell amplicon and whole genome sequencing. Collectively, these studies demonstrate that single cell analysis can be successfully used and implemented in a forensic setting, providing significant advantages over current methods in many situations encountered in casework.