Bardole DNA Collection Method
The following was developed by Francine Bardole of the West Jordan Utah Police Department with support from M-Vac Systems. This is a concept technique and is still under research. Some researchers have mistakenly called it an M-Vac method, but the M-Vac is not used in this DNA collection technique. It is a method of separating and isolating DNA material from small evidence items. The application could include many items that are currently difficult to sample like shell casings, fingernail clippings, rings, gun parts, keys, bomb fragments and other small items. Here is the basic concept.
The Bardole Method Overview:
Add sterile SRS buffer to a sterile collection bottle- Place the evidence item in the bottle
- Agitate using a vortex type mixing device
- Attach a concentration filter to the SEC vacuum hose and turn ON the vacuum
- Swirl and pour the liquid portion of the collection bottle into the concentration filter cup
- If the evidence item is heavy or sharp, trap the item with a sterile instrument
, so that is does not fall onto the filter membrane and potentially damage the integrity - The DNA material is retained on the filter membrane
- When finished, remove the concentration filter from the vacuum tube and cover to dry
Later, when it is time to process the filter membrane, it will be cut out of the concentration filter apparatus and processed in the same manner as a swab or other DNA evidence gathering method is processed.
Continuing Research
A multiple agency project is underway with a larger data set of shell casings to further determine the sensitivity of the method.
Adjudicated Case
Ten casings from a road-rage shooting were processed using the method described above. The extraction quant yielded 0.847 ng of DNA. The amplified results yielded a comparable major profile that matched the suspect. The evidence was presented in court, challenged and accepted.
References:
https://www.forensicmag.com/news/2018/04/dna-spent-shell-casings-matter-getting-nooks-and-crannies