This technical summary reports on a project that had the main goal of developing and optimizing a method to identify and recover male cells from a mixture of male and female like-cells, such as epithelial cells, in order to improve the sensitivity and resolution of DNA analyses when analyzing samples composed of male and female like-cells.
The author of this technical summary report lays out the research goals, objectives, and outcomes of a project aimed at developing and optimizing a method to identify and recover male cells from a mixture of male and female like-cells by targeting, or immunostaining, the male Y-chromosome with a chromosome paint followed by the use of DEPArray NxT to detect and recover the male cells. The researchers combined two methods in to a single, unified protocol for use in forensic DNA analysis. The primary research question was to determine if it is possible to selectively label and recover male epithelial cells in a mixture with female epithelial cells. Two more detailed research questions asked if a commercially available method to label human Y-chromosome could be modified to successfully stain cells in suspension; and given the success of the previous question, if the method could be transitioned successfully to detect and recover the male epithelial cells using DEPArray NxT or DEPArray PLUS. Results demonstrated methods that had a staining efficiency of 80% or greater when using freshly collected cells, and translated well to the staining of lower quality cells. The author also notes the collection of male cells when removed in groups showed to be successful in 1:1 and 1:10 dilutions of male to female epithelial cells where female alleles were detected in two samples, though other dilutions appeared to be less robust, improvements might be possible using DEPArray PLUS. The author suggests a variety of benefits including the presentation of a method that can target and recover male epithelial cells to obtain an interpretable male profile, which may result in stronger statistical support for analysts’ results and allow the profiles to be uploaded to CODIS (Combined DNA Index System), along with implications for criminal investigation or trial.