Analysis of M-Vac buffer flow-through for the presence of cell-free DNA in saliva
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Citation
Abstract
Collection methods for biological forensic samples have improved over the years, including the development of the Microbial Vacuum, M-VacTM. The M-VacTM is used to collect potential biological samples that are not readily visible, particularly on large substrates or evidence items. The M-VacTM uses a wet vacuum filtration method that collects the cellular material on a filter membrane, while the buffer that flows through the filter is discarded. This study assesses whether genetic material is present in the filtrate after collection and tests different filter pore sizes and membrane materials for the retention of cell-free deoxyribonucleic acid, or cfDNA. When pre-extracted DNA was filtered through 0.45 micron and 0.2 micron membranes, only approximately one quarter of the cfDNA was retained on the filter. In mixture samples that contained cellular material from whole saliva and cfDNA, the filters were able to retain more than 80% of the genetic material that was deposited onto the membrane. Similar DNA profiles and yields were obtained using both pore sizes. The cellulose nitrate filter membranes had a higher yield than the polyethersulfone filters and resulted in profiles with more alleles and genetic information detected on the filter.
Description
2025