Boston University researchers announced today that the Journal of Forensic Identification published their research in the September, 2014 edition. JFI is a major, peer-reviewed journal and the Boston University research is the first to be published in such a journal. As a new tool in the forensic DNA collection market, the M-Vac System clears a significant hurdle by being highlighted in a major study that is then published in a prestigious journal.
In the study, researchers compared the M-Vac System to swabbing and taping on a variety of substrates. The M-Vac System proved to be an important option, especially in collecting DNA material from porous and rough substrates like denim and carpet. The following is taken from the abstract of the publication:
Traditional biological collection methods are compared to a wet-vacuum system through the collection of different volumes of blood on tile, denim, and carpet. The wet-vacuum technique was able to recover sufficient amounts of blood for Kastle-Meyer presumptive testing. Although it was possible to detect blood after wet-vacuum collection, swabbing resulted in the highest rate of positive results for the presumptive test.
The DNA yields and detection limits that were obtained when collecting from tile were similar between methods, suggesting they are equivalent in their ability to collect DNA from nonporous surfaces. When the techniques were tested on mock case surfaces, wet-vacuum collection resulted in higher DNA yields than either the double swab or taping methods. However, STR profiles that were obtained from these mock surfaces exhibited extraneous alleles at many loci, suggesting that these higher yields were the result of collecting DNA already present on the substrate.
The wet-vacuum collection efficacy was further tested by examining yields that were obtained when semen and blood were collected from tile, denim, carpet, and brick. Results show that the technique was successful in collecting DNA from all surfaces, although the yield from brick varied widely and was low compared to the other substrates. Of the 16 low-volume samples collected from brick, 8 resulted in no detectable DNA.
The wet-vacuum collection technique is a potentially useful tool in forensic casework environments. Data indicate this technique may be most valuable for collection of low-level biological evidence in low-traffic areas.
A full copy of the article can be downloaded from the M-Vac System website by clicking here.