A Phenol-Free DNA Extraction Method

In this application note by Molecular Devices, a DNA extraction method is evaluated as an alternative to a conventional phenol/chloroform extraction for pretreatment of biopharmaceutical samples. A number of protein samples were extracted using this procedure and then tested in the Threshold Total DNA Assay. This extraction procedure incorporates a chaotrope, sodium iodide, an anionic detergent, sodium N-lauroyl sarcosinate, and isopropanol to co-precipitate nucleic acids with a polysaccharide carrier, glycogen. This precipitation allows the separation of DNA from sample components, proteins, lipids, and buffers that may interfere with the Total DNA Assay. For many proteins, this extraction technique can replace a conventional overnight digest with Proteinase K and SDS, and/or a phenol/chloroform extraction.