Isolation of Nucleic Acids Using Silica-Gel Based Membranes: Methods Based on the Use of QIAamp Spin Columns

Abstract

The adsorption of nucleic acids to the surface of glass or silica in the presence of high concentrations of chaotropic salts was firstly described by Vogelstein and Gillespie (5) who recovered DNA fragments from agarose gels using glass powder. This technology has now been further developed and efficient lysis protocols have been established for a variety of complex starting materials. Selective binding of DNA or RNA has been achieved through the use of modified silica-gel surfaces and binding and wash buffers have been optimized to allow maximum discrimination between nucleic acids. After lysis of the starting material, the sample is adjusted to promote binding of the desired nucleic acid to the membrane. Polysaccharides and proteins do not bind and are removed. The bound nucleic acid is washed with alcohol containing buffers for desalting.