Combined DNA Typing and Protein Identification from Unfired Brass Cartridges
Biological evidence in the form of contact traces is of major importance in forensic laboratories but success rates are affected by the low amounts and degraded state of the DNA present on these items. Combining DNA polymorphisms with markers individualizing the more abundant protein fraction is a promising new approach. In this study touched brass cartridges were successfully tested for DNA polymorphisms and signature peptides after a single collection and enzyme digestion step. A comparison between moistened swabs and adhesive tape for the collection step resulted in slightly better quality DNA profiles for the tape samples, but no significant difference for protein identifications. The detected proteins showed the expected prominence of different keratins and were generally consistent with previously described skin proteomes.