Detection of latent DNA

Diamond dye is relatively inexpensive, simple to apply, binds to the DNA in 3 s or less, has no mutagenic effects at the concentrations used, does not affect subsequent DNA profiling, and does not bind effectively to bacterial DNA. In combination with a mini-fluorescence microscope, this proof-of-concept study shows that otherwise invisible DNA deposited by touch can be visualised. The position and amount of cellular material deposited during even brief contact can be recorded allowing targeted sampling in any further DNA typing of forensically-significant items.