Spatially inhomogenously functionalized porous media and method for use in selective removal of contaminants
Compositions and methods for separating double-stranded nucleic acids out of a mixture comprising single-stranded nucleic acids and/or dNTPs and/or enzymes. The method uses spatially inhomogeneously functionalized nanoporous materials. For example, the compositions and methods of the present invention can be used to purify DNA amplification reaction products.
1. A silica nanoporous material, comprising:
an internal pore surface that defines pores from 2 to 300 nm in diameter in the silica nanoporous material and an external non-pore surface; wherein the internal pore surface has primary, secondary, or tertiary amine groups covalently bound thereto; and the external non-pore surface is functionalized with a polyacrylic acid copolymer.
2. The silica nanoporous material of claim 1 , wherein the polyacrylic acid copolymer is a polyacrylamide-co-acrylic acid copolymer.
3. The silica nanoporous material of claim 1 , wherein the polyacrylic acid copolymer is a polyacrylic acid-polyethylene copolymer or polyacrylic acid-polystyrene copolymer.
4. The silica nanoporous material of claim 1 , wherein the internal pore surface has the primary amine groups.
5. The silica nanoporous material of claim 4 , wherein the primary amine groups are alkylamine groups.
6. The silica nanoporous material of claim 5 , wherein the alkylamine groups are aminopropyl groups.
7. The silica nanoporous material of claim 4 , wherein the primary amine groups are aminosilane groups.
8. The silica nanoporous material of claim 7 , wherein the aminosilane groups are aminopropyltrimethoxysilane groups.
9. A bead, comprising: the silica nanoporous material of claim 1 , wherein the bead has a diameter of from 40 to 60 μm.
10. A bead, comprising: the silica nanoporous material of claim 1 , wherein the bead has a diameter of from 60 to 200 μm.
11. The silica nanoporous material of claim 1 , wherein the internal pores are 60 or 150 Å in diameter.
12. A method for separating double-stranded nucleic acids from single-stranded nucleic acids and/or free nucleotides, comprising:
a) contacting a mixture comprising the double-stranded nucleic acids and single-stranded nucleic acids and/or free nucleotides with the silica nanoporous material of claim 1 ;
b) incubating the mixture and the silica nanoporous material, wherein at least a portion of the single-stranded nucleic acids and/or free nucleotides are selectively adsorbed to the internal pore surface; and
c) isolating the silica nanoporous material, thereby separating at least a portion of the double-stranded nucleic acids from the single-stranded nucleic acids and/or free nucleotides.
13. The method of claim 12 , wherein the mixture and silica nanoporous material are incubated for from 5 to 60 seconds.
14. The method of claim 12 , wherein the mixture and silica nanoporous material are incubated for from 30 to 45 seconds.
15. The method of claim 12 , wherein the silica nanoporous material is isolated by centrifugation or filtration.
16. The method of claim 12 , wherein the double-stranded nucleic acid is DNA.
17. The method of claim 12 , wherein the mixture is a PCR product mixture.