The development of a method of suspension RNA-FISH for forensically relevant epithelial cells using LNA probes

Messenger RNA profiling is becoming a common method for body fluid identification in forensic science but there are disadvantages when cell mixtures are present from more than one individual. A method that could identify and separate such cell mixtures would simplify downstream analysis. To do this, we have developed a novel method of RNA suspension-fluorescent in situ hybridization (RNA S-FISH) using a locked nucleic acid (LNA) probe for the keratin 10 (KRT10) mRNA that is suitable as a potential marker for epithelial cells. As sample size may be restricted in forensic samples, this method has focused on minimizing cell loss whilst maintaining signal strength. Furthermore, we have shown that it is possible to obtain full DNA profiles from 150 RNA S-FISH labeled cells isolated using laser microdissection.