Spin column-based isolation of genomic DNA from forensic samples—NucleoSpin DNA Forensic

NucleoSpin DNA Forensic is designed for small-scale preparation of highly pure genomic DNA from buccal swabs, as well as small amounts of any tissue, cells, or other forensic samples, such as dried blood spots, “trace and touch” samples, or cigarette filters. The purified DNA can be used directly as template for PCR, or any kind of enzymatic reaction. If sample carriers such as buccal swabs are used, it is necessary to remove the carrier after incubation with the lysis buffer. NucleoSpin Forensic Filters are recommended for efficient and convenient carrier removal. The filters allow a long-term incubation of lysis buffer and sample, followed by an easy and fast separation using centrifugation. The kit provides reagents for the purification of up to 7 μg of pure genomic DNA from suitable samples (typical yields for DNA isolation from buccal swabs: 1–3 μg DNA). Depending on the elution volume used, concentrations of 10–30 ng/μl can be obtained.

The NucleoSpin DNA Forensic procedure is based on reversible adsorption of nucleic acids to the silica membrane in the NucleoSpin DNA Forensic Columns under appropriate buffer conditions. Lysis is achieved by incubation of samples with Proteinase K at 56 °C. For the adjustment of binding conditions under which nucleic acids bind to the silica membrane, binding buffer is added to the lysate. After binding, the silica membrane is washed three times to remove contaminants and salts using two different wash buffers. Residual ethanol from the previous wash steps is removed by a drying step. Highly purified DNA is eluted with low-salt elution buffer and can directly be used for downstream applications.