Compositions and methods of selective nucleic acid isolation
View Patent ↗The invention relates to methods for isolating and/or identifying nucleic acids. The invention also provides kits for isolating and/or identifying nucleic acids.
1. A method for isolating DNA and RNA from a biological sample comprising:
selectively binding DNA to a first solid phase by contacting the biological sample with the first solid phase under conditions which selectively bind DNA;
separating the first solid phase with the bound DNA from a first unbound portion of the biological sample;
isolating the DNA from the first solid phase; and
isolating RNA from the first unbound portion of the biological sample, wherein the isolating of the RNA from the first unbound portion of the biological sample comprises:
exposing the first unbound portion of the biological sample to a second solid phase under conditions which bind RNA to the second solid phase, wherein the conditions which bind RNA to the second solid phase comprise a neutral or acidic pH;
separating the second solid phase with bound RNA from a second unbound portion of the biological sample; and
isolating the RNA from the second solid phase.
2. The method of claim 1 , wherein the isolating the DNA from the first solid phase comprises eluting the DNA.
3. The method of claim 1 , wherein the isolating of the RNA from the second solid phase comprises eluting the RNA.
4. The method of claim 1 , wherein the second solid phase is a siliceous material.
5. The method of claim 4 , wherein the siliceous material is selected from at least one of silica, silica dioxide, diatomaceous earth, glass, Celite, and silica gel.
6. The method of claim 1 , wherein the second solid phase is in a form selected from at least one of a particle, a bead, a membrane, a frit, a surface within a chamber, and a side of a container.
7. The method of claim 1 , wherein the conditions which selectively bind DNA comprise using a binding buffer comprising:
an alkaline pH; and
a large anion, wherein the large anion is at least as large as a bromide ion.
8. The method of claim 7 , wherein the large anion is selected from at least one of picrate, tannate, tungstate, molybdate, perchlorate, and sulfosalicylate.
9. The method of claim 7 , wherein the large anion is selected from at least one of trichloroacetate, tribromoacetate, thiocyanate, and nitrate.
10. The method of claim 7 , wherein the large anion is selected from at least one of iodide and bromide.
11. The method of claim 7 , wherein the alkaline pH is equal to, or above 8.0.
12. The method of claim 7 , wherein the alkaline pH is equal to, or above 9.0.
13. The method of claim 7 , wherein the alkaline pH is equal to, or above 10.0.
14. A method of isolating nucleic acid from a biological sample comprising:
binding nucleic acid to a first solid phase by contacting the biological sample with the first solid phase under conditions which bind both RNA and DNA;
separating the first solid phase with bound nucleic acid from a first unbound portion of the biological sample;
eluting RNA from the first solid phase with bound nucleic acid under conditions which selectively bind DNA;
removing the first solid phase with bound DNA from a first eluate; and
isolating the DNA from the first solid phase.
15. The method of claim 14 , wherein the isolating the DNA from the first solid phase comprises eluting the DNA from the first solid phase.
16. The method of claim 14 , wherein the first solid phase is a siliceous material.
17. The method of claim 16 , wherein the siliceous material is selected from at least one of silica, silica dioxide, diatomaceous earth, glass, Celite, and silica gel.
18. The method of claim 17 , wherein the first solid phase is in a form selected from at least one of a particle, a bead, a membrane, a frit, a surface within a chamber, and a side of a container.
19. The method of claim 14 , wherein the conditions which selectively bind DNA comprise using a binding buffer comprising:
an alkaline PH; and
a large anion, wherein the large anion is at least as large as a bromide ion.
20. The method of claim 19 , wherein the large anion is selected from at least one of picrate, tannate, tungstate, molybdate, perchlorate, and sulfosalicylate.
21. The method of claim 19 , wherein the large anion is selected from at least one of trichloroacetate, tribromoacetate, thiocyanate, and nitrate.
22. The method of claim 19 , wherein the large anion is selected from at least one of iodide and bromide.
23. The method of claim 19 , wherein the alkaline pH is equal to, or above 8.0.
24. The method of claim 19 , wherein the alkaline pH is equal to, or above 9.0.
25. The method of claim 19 , wherein the alkaline pH is equal to, or above 10.0.
26. The method of claim 14 , further comprising:
exposing the first eluate to a second solid phase under conditions which bind RNA to the second solid phase;
separating the second solid phase with the bound RNA from an unbound portion of the first eluate; and
isolating the RNA from the second solid phase.
27. The method of claim 26 , wherein the isolating the RNA from the second solid phase comprises eluting the RNA.
28. The method of claim 26 , wherein the second solid phase is a siliceous material.
29. The method of claim 28 , wherein the siliceous material is selected from at least one of silica, silica dioxide, diatomaceous earth, glass, Celite, and silica gel.
30. The method of claim 29 , wherein the second solid phase is in a form selected from at least one of a particle, a bead, a membrane, a frit, a surface within a chamber, and a side of a container.
31. The method of claim 26 , wherein the conditions which bind RNA to the second solid phase comprise a neutral or acidic pH.
32. The method of claim 26 , wherein the conditions which selectively bind DNA comprise using a binding buffer comprising:
an alkaline PH; and
a large anion, wherein the large anion is at least as large as a bromide ion.
33. The method of claim 32 , wherein the conditions which bind RNA to the second solid phase comprise a neutral or acidic pH.
34. A method for identifying DNA and RNA in a biological sample comprising:
selectively binding DNA to a first solid phase by contacting the biological sample with the first solid phase under conditions which selectively bind DNA;
separating the first solid phase with the bound DNA from a first unbound portion of the biological sample;
exposing the first unbound portion of the biological sample to a second solid phase under conditions which bind RNA to the second solid phase, wherein the conditions which bind RNA to the second solid phase comprise a neutral or acidic pH;
separating the second solid phase with bound RNA from a second unbound portion of the biological sample;
identifying the DNA bound to the first solid phase; and
identifying the RNA bound to the second solid phase.
35. The method of claim 34 , wherein the identifying the DNA bound to the first solid phase comprises amplifying the DNA bound to the first solid phase.
36. A method of identifying nucleic acid in a biological sample comprising:
binding nucleic acid to a first solid phase by contacting the biological sample with the first solid phase under conditions which bind both DNA and RNA;
separating the first solid phase with bound nucleic acid from a first unbound portion of the biological sample;
eluting RNA from the first solid phase with bound nucleic acid under conditions which selectively bind DNA;
removing the first solid phase with bound DNA from a first eluate; and
identifying the DNA bound to the first solid phase.
37. The method claim 36 , wherein the identifying the DNA bound to the first solid phase comprises amplifying the DNA bound to the first solid phase.