The FBI Laboratory Division presented a summary of their completed research as of April 2019 at the Southern Association of Forensic Scientists (SAFS) annual meeting in Asheville, NC. They are evaluating the M-Vac® system. Their research includes four phases.
- Phase 1 - Quality Assurance
- Phase 2 - Compare SOP vs. M-Vac® on large objects
- Phase 3 - Compare SOP vs. M-Vac® on small objects
- Phase 4 - M-Vac® after swabbing on large and/or small objects
Phase 1 and a portion of phase 2 were presented. In phase 1, the collection buffer and filter units were found to be absent of contaminants. In phase two, the swab and M-Vac® were compared on glass, pressure treated wood, plywood, wooden countertop, automotive carpet and drywall. The size of the test templates ranged from 13x13 cm to 10x23 cm, but the inoculation area was ~100 cm2. They were large samples for a swab and normal to small samples for the M-Vac®. Blood, diluted 1:100 in sterile buffer, was used as the inoculate. The table below presents their findings.
As shown on the graph, the M-Vac® performed significantly better in four of the experiments. It collected 5 times more DNA material on pressure-treated wood, 7 times more on plywood, 47 times more on automotive carpet and 28 times more on pine. In the other three experiments, the results between the two methods were similar.
The investigators' conclusions from the research that has been completed are straightforward. The M-Vac® may provide an alternative collection method on porous surfaces and when the swab is unsuccessful. Swabbing may be a more convenient collection method on flat non-porous surfaces and it may be more simple and affordable. Below is the full presentation.
Acknowledgements: This research is being conducted by the Counterterrorism and Forensic Science Research Unit, Laboratory Division, Federal Bureau of Investigations by Jessica M. McLamb, MS, and Mark F. Kavlick, PhD. We appreciate their efforts. This research does not constitute endorsement by the FBI. The conclusions are those of the researchers and should not be construed as necessarily representing the official policies, either express or implied, of the U.S. Government. The full presentation and contact details are available upon request (