Isolation of nucleic acids

Abstract

A method for extracting nucleic acids from a biological material such as blood comprises contacting the mixture with a material at a pH such that the material is positively charged and will bind negatively charged nucleic acids and then eluting the nucleic acids at a pH when the said materials possess a neutral or negative charge to release the nucleic acids. The nucleic acids can be removed under mildly alkaline conditions to the maintain integrity of the nucleic acids and to allow retrieval of the nucleic acids in reagents that are immediately compatible with either storage or analytical testing.

1 - 41 . (canceled) 
     
     
         42 . A method for extracting a nucleic acid from a biological material comprising:
 contacting the biological material with a solid phase wherein the solid phase at a first pH, at which the solid phase is positively charged, reversibly binds nucleic acid present in the biological material, and at a second, higher, pH at which the charge on the solid phase is negative, neutral or less positive releases the nucleic acid,   wherein the solid phase is controlled pore glass, a polysaccharide, a ceramic material, a porous plastic material, a plastic material, polystyrene bead, bead, particle, tube, well, probe, dipstick, pipette tip, slide, fiber, membrane, paper, cellulose, agarose, glass or plastic, and wherein the nucleic acid is released at a pH of less than 10.5 and an ionic strength of less than 1M.   
     
     
         43 . The method of  claim 42 , wherein the solid phase is a charge switchable ion exchange resin having a positive charge that can be reversed or neutralized by changing the pH above its pKa. 
     
     
         44 . The method of  claim 43 , wherein the solid phase comprises a plurality of ionizable groups selected from the group consisting of nucleotides, polyamines, and imidazoles. 
     
     
         45 . The method of  claim 43 , wherein the solid phase has a pKa of from 4.5 to 8.5. 
     
     
         46 . The method of  claim 42 , wherein the nucleic acid binds the solid phase at a pH of less than 6 and is released from the solid phase at a pH of greater than 8. 
     
     
         47 . The method of  claim 42 , wherein the nucleic acid is released at an ionic strength of less than 500 mM. 
     
     
         48 . The method of  claim 47 , wherein the nucleic acid is released at an ionic strength of less than 100 mM. 
     
     
         49 . The method of  claim 48 , wherein the nucleic acid is released at a pH of less than 10.0. 
     
     
         50 . The method of  claim 49 , wherein the nucleic acid is released at a pH of less than 9.0. 
     
     
         51 . A composition comprising a solid phase wherein the solid phase at a first pH, at which the solid phase is positively charged, reversibly binds nucleic acid present in a biological material, and at a second, higher, pH at which the charge on the solid phase is negative, neutral or less positive releases the nucleic acid,
 wherein the solid phase is controlled pore glass, a polysaccharide, a ceramic material, a porous plastic material, a plastic material, polystyrene bead, bead, particle, tube, well, probe, dipstick, pipette tip, slide, fiber, membrane, paper, cellulose, agarose, glass or plastic, and wherein the nucleic acid is released at a pH of less than 10.5 and an ionic strength of less than 1M.   
     
     
         52 . The composition of  claim 51 , wherein the solid phase is a charge switchable ion exchange resin having a positive charge that can be reversed or neutralized by changing the pH above its pKa. 
     
     
         53 . The composition of  claim 51 , wherein the solid phase comprises a plurality of ionizable groups selected from the group consisting of nucleotides, polyamines, and imidazoles. 
     
     
         54 . The composition of  claim 52 , wherein the solid phase has a pKa of from 4.5 to 8.5.