DNeasy mericon Food Kit
This kit uses an improved cetyltrimethylammonium bromide (CTAB) extraction of total cellular nucleic acids. The nonionic detergent CTAB is widely used for the efficient extraction of total cellular nucleic acids from a wide range of tissue types. Depending on the salt conditions, CTAB may complex with cellular nucleic acids (low-salt conditions) or complex with cellular inhibitors, such as polysaccharides, proteins and plant metabolites (high-salt conditions; as found in the Food Lysis Buffer).
With fewer workflow steps than conventional CTAB protocols, up to 30 samples can be processed in 2.5 hours with the DNeasy mericon Food Kit (see the figure " Efficient and rapid DNA extraction").
The optimized protocol uses CTAB in combination with Proteinase K to digest compact tissue and subsequently precipitate proteins with simultaneous precipitation of other cellular and food-derived inhibitors.
Inhibitors are precipitated by centrifugation, while the extracted DNA remains in solution. In the subsequent chloroform extraction, any remaining CTAB-protein, CTAB-debris or CTAB-polysaccharide complex not precipitated is removed together with other lipophilic inhibitors by extraction into the organic chloroform phase. Only the aqueous phase containing the DNA and significantly depleted inhibitors is processed further. This phase is mixed with binding buffer (to adjust binding conditions) and applied to the QIAquick Spin Columns. The resulting DNA is immediately ready for use in a downstream mericon real-time PCR assay.
mericon DNA Bacteria Kit and mericon DNA Bacteria Plus Kit
To date, the predominant method to test food for the presence of pathogens has been via culture preparation and/or ELISA-based assays. Molecular-based methods, specifically real-time PCR, offer an informative complement to these well-established methods.
The thermal lysis protocol of the mericon DNA Bacteria Kit is optimized for the majority of easily lysed Gram-negative bacteria (e.g., Salmonella spp., Camplylobacter spp. and Cronobacter spp.). The mechanical lysis protocol of the mericon DNA Bacteria Plus Kit creates the appropriate conditions for bacterial extraction from Gram-positive bacteria, such as Listeria spp.
The carefully formulated chemistry included in the mericon DNA Bacteria Kit and mericon DNA Bacteria Plus Kit maximizes lysis efficiency, stabilizes the extracted DNA and removes inhibitors that may interfere with downstream applications.