Researchers at Boston University successfully published their work in the Journal of Forensic Identification in September of 2014. This is a major accomplishment for the researchers and Boston University. It is also a significant event for M-Vac Systems, as it is the first peer-reviewed forensics journal to publish an article highlighting comparative research between the M-Vac System and other DNA collection methods, namely swabbing and taping. Below is the abstract and the conclusion of the article. Click here for a PDF of the full article.
Abstract: 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. If wet-vacuum technology is to be utilized, then probative evidence in the vicinity of the stain which is to be vacuumed should be collected first.