DNA purification by solid phase extraction using a hydroxide-washed glass fiber membrane

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a modified glass fiber membrane which exhibits sufficient hydrophilicity and sufficient electropositivity to bind DNA from a suspension of cellular components and permit elution of the DNA from the membrane.
It has been found that much lower concentrations of chaotropes or alcohols can be utilized to achieve purification of DNA using the instant modified glass fiber membranes.
Binding of DNA to the modified glass fiber membranes allows the use of such membranes for automated DNA isolation processes and for sample processing steps for DNA probe tests.
For example, using a dot-blot apparatus, 96 samples can be done at once, and rapidly.
DNA interacts with a solid phase surface in two ways.
First, DNA interacts with the surface through hydrogen bonding between hydroxyl groups of DNA and surface components of the solid phase, such as surface hydroxyls.
The second interaction is between the negatively charged phosphates of the DNA and positively charged elements of the solid phase surface.
The hydrophilic and electropositive characteristics of the solid phase surface must be such as to allow binding of the DNA from a suspension of cellular components, a suspension of nucleic acids and other materials and/or a suspension of nucleic acids, and to permit elution of the DNA from the solid phase material.
Thus, the electropositive characteristics of the solid phase material cannot have too high of a positive charge, or the DNA will stick to the surface and cannot be eluted.
This characteristic is also true for many metal-based surfaces, which has resulted in their inability to be utilized for purification of DNA.
Silicon-containing materials, e.
g.
, silica, Celite, glass powders and the like, have been used for DNA purification with mixed results.
Some of these surfaces have low binding capacities and/or require the use of highly concentrated solutions of chaotropes or alcohols for the binding of DNA.
Thus, it is desired to produce solid phase surfaces, particularly solid phases of modified glass fiber membranes, which exhibit suitable hydrophilic and electropositive characteristics for DNA purification and/or for DNA purification with much lower concentrations of chaotropes or alcohols