Forensics for Protein Fingerprinting

Analysis of trace samples have tremendous value in forensic applications. DNA recovered from trace samples can provide unambiguous contributor identification through analysis of short tandem repeat (STR) and single nucleotide polymorphisms (SNP). However, trace DNA samples have intrinsic limitations that reduce the likelihood of contributor identification. The low DNA yield (frequently less than 1 ng) from trace samples is further complicated by potential DNA damage caused by environmental factors, as well as poor collection efficiency and/or release of DNA from conventional swabs from a variety of relevant surfaces. GE has a long history in the successful development of ultrasensitive and forensic applications and associated technology. The goal of our program is to identify individuals via polymorphisms in their proteins, instead of traditional methods (i.e. polymorphisms in DNA sequences). To accomplish this, the team will develop technologies to detect genetically variable peptides (GVP) from touch samples. This approach will be used to identify individuals within mixed contributor samples. The realization of this goal requires the development of numerous technical innovations around maximizing recovery of limited protein in touch samples; development of efficient mass spectrometry protocols for identification of GVPs from low abundance samples; identifying GVP panels that produce random match probabilities of 10-9, and identification of individuals from mixed contributor samples.