Purification method and kits

1. A method for separating nucleic acid from other components in a crude liquid sample, said method comprising the steps of applying a liquid sample containing or suspected of containing said nucleic acid to a sample receiving section of a bibulous membrane which does not carry any specific binding agents for nucleic acids, causing said liquid sample to flow along the bibulous membrane, so that nucleic acid is distributed along the length of the membrane and sufficiently separated from other components in the liquid sample to allow detection thereof and thereafter, detecting nucleic acid on or recovering nucleic acid from a region of said membrane which is spaced from the sample receiving section.

2. A method according to claim 1 further comprising the step of drying the membrane after the liquid has flowed along it.

3. A method according to claim 2 further comprising the step of storing the dried membrane.

4. A method according to claim 1 further comprising subjecting separated nucleic acid to further analysis.

5. A method according to claim 4 wherein the further analysis is conducted using a sample of the membrane.

6. A method according to claim 4 wherein nucleic acid is eluted from the membrane prior to said further analysis.

7. A method according to claim 4 wherein the further analysis comprises SNP typing, DNA fingerprinting or sequencing.

8. A method according to claim 4 wherein a specific target nucleic acid is detected.

9. A method according to claim 4 wherein the membrane is a nitrocellulose membrane.

10. A method according to claim 4 wherein the membrane is an element of a liquid flow device.

11. A method according to claim 10 wherein the liquid flow device comprises a sample receiving section and an absorbent section arranged remotely from the sample receiving section on the membrane.

12. A method according to claim 1 wherein the membrane is accommodated within a solid housing or the membrane is laminated.

13. A method according to claim 1 wherein the membrane is processed so as to enhance the wicking of liquid therealong.

14. A method according to claim 1 wherein the sample is a physiological or clinical sample or a tissue extract.

15. A method according to claim 11 wherein the sample is an extract of a plant or animal tissue.

16. A method according to claim 11 wherein the sample is blood, serum, urine, milk or saliva or a faecal extract.

17. A method according to claim 1 wherein the sample is an environmental sample.

18. A method according to claim 17 wherein the sample is a water sample or a soil extract.

19. A method according to claim 1 , wherein said nucleic acid is a target nucleic acid and said detecting comprises detecting the presence of the specific target nucleic acid.

20. A method according to claim 1 wherein a section of the membrane is taken after the sample has been allowed to run along it, and the presence of nucleic acid detected thereon.

21. A method according to claim 20 wherein the nucleic acid is detected using a nucleic acid amplification reaction.

22. A method according to claim 21 wherein a reagent useful in said nucleic acid amplification reaction is present on the membrane after the sample has flowed therealong.

23. A method according to claim 22 wherein the said reagent is present on the membrane before the application of the sample.

24. A method according to claim 22 wherein the said reagent is present in a sample receiving section, and is transferred along the membrane in conjunction with the sample.

25. A method according to claim 22 wherein the said reagent is an amplification primer.

26. An method according to claim 21 wherein the amplification reaction is a polymerase chain reaction (PCR).

27. A method according to claim 26 wherein the progress of the PCR is monitored in real-time.

28. A method according to claim 27 wherein amount of sample applied to the membrane is known and the results of the monitoring are used to quantitate the amount of nucleic acid present.

29. A method according to claim 1 wherein the presence of more than one nucleic acid one the membrane is detected.

30. A method according to claim 29 wherein multiple PCR reactions are conducted using the same or different samples of the membrane.

31. A method according to claim 29 wherein a multiplex PCR reaction is conducted to allow more than one nucleic acid to be detected in a single PCR.

32. A method according to claim 1 wherein more than one nucleic acid is recovered from the membrane.

33. A method according to claim 1 wherein the membrane further comprises at least one immunologically reactive reagent for conducting an immunoassay of said liquid sample.

34. A method according to claim 33 wherein the at least one immunologically reactive reagent comprises antibodies.

35. A method of claim 33 further comprising detecting the presence or absence of an immunologically reactive analyte in said liquid sample by said immunoassay.

36. A method according to claim 33 wherein the membrane further comprises a labelled binding agent diffusibly arranged thereon.

37. A method according to claim 35 wherein the said analyte and nucleic acid originate from the same organism, or a particular species of the same organism or a particular genotype of the same organism.

38. A method according to claim 37 wherein the analyte is characteristic of a type of organism, and the nucleic acid is characteristic of a particular species of said organism.

39. A method according to claim 35 wherein one of the analyte or nucleic acid is characteristic of a particular infective organism, and the other is characteristic of a host of said organism.

40. A method according to claim 39 wherein the analyte is characteristic of an infective organism, and the nucleic acid is found in a gene of the host which impacts on the host's susceptibility or resistance to said organism.

41. A method according to claim 35 wherein the analyte is a pesticide applicable to a plant and the nucleic acid is found in a gene of the plant.

42. A method for separating nucleic acid from other components in a liquid sample, said method comprising the steps of applying a liquid sample containing or suspected of containing said nucleic acid to a sample receiving section of a bibulous membrane which does not carry any specific binding agents for nucleic acids, causing said liquid sample to flow along the bibulous membrane, so that nucleic acid is distributed along the length of the membrane and sufficiently separated from other components in the liquid sample to allow detection thereof and thereafter, drying and storing said membrane in a manner allowing subsequent detection of nucleic acid on or recovery of nucleic acid from a region of said membrane which is spaced from the sample receiving section.