Hybridization compositions and methods using formamide

1. A method of hybridizing nucleic acid sequences comprising:

providing a first nucleic acid sequence,

providing a second nucleic acid sequence,

providing a hybridization composition comprising formamide, and

combining the first and the second nucleic acid sequence and the hybridization composition for at least a time period sufficient to hybridize the first and second nucleic acid sequences, wherein the time period is less than 4 hours, and wherein the hybridization is before a stringent wash,

wherein the concentration of formamide is 10% to 25% v/v;

wherein the hybridization composition further comprises 15% to 80% w/v of an accelerating agent and 400 mM to 1200 mM of a salt.

2. A method of hybridizing nucleic acid sequences comprising:

providing a first nucleic acid sequence in an in situ biological sample,

applying a hybridization composition comprising a second nucleic acid sequence and formamide to said first nucleic acid sequence for at least a time period sufficient to hybridize the first and second nucleic acid sequences, wherein the time period is less than 4 hours,

wherein the formamide is present in a concentration of 10% to 25% v/v;

wherein the hybridization composition further comprises 15% to 80% w/v of an accelerating agent and 400 mM to 1200 mM of a salt.

3. The method according to claim 1 , wherein a sufficient amount of energy to hybridize the first and second nucleic acids is provided.

4. The method according to claim 3 , wherein the energy is provided by heating the hybridization composition and nucleic acid sequence.

5. The method according to claim 4 , wherein the heating step is performed by the use of microwaves, hot baths, hot plates, heat wire, peltier element, induction heating or heat lamps.

6. The method according to claim 1 , wherein the first nucleic acid sequence is double stranded and the second nucleic acid is single stranded.

7. The method according to claim 1 , further comprising a denaturation step, wherein the denaturation and the combining occur separately.

8. The method according to claim 1 , wherein the combining includes steps of heating and cooling the hybridization composition and nucleic acid sequences.

9. The method according to claim 1 , wherein the time period sufficient to hybridize the first and second nucleic acid sequences is less than 2 hours.

10. The method according to claim 9 , wherein the time period sufficient to hybridize the first and second nucleic acid sequences is less than 1 hour.

11. The method according to claim 10 , wherein the time period sufficient to hybridize the first and second nucleic acid sequences is less than 30 minutes.

12. The method according to claim 11 , wherein the time period sufficient to hybridize the first and second nucleic acid sequences is less than 5 minutes.

13. The method according to claim 1 , further comprising a denaturation step performed at 72 to 92° C.

14. The method according to claim 1 , further comprising a denaturation step performed at 75 to 95° C.

15. The method according to claim 1 , further comprising a denaturation step performed at 85° C.

16. The method according to claim 1 , further comprising a denaturation step performed at 82° C.

17. The method according to claim 1 , further comprising a denaturation step which takes less than 15 minutes.

18. The method according to claim 17 , further comprising a denaturation step which takes less than 5 minutes.

19. The method according to claim 1 , wherein the first nucleic acid sequence is in a biological sample.

20. The method according to claim 19 , wherein the biological sample is a cytology or histology sample.

21. The method according to claim 1 , further comprising a blocking step.

22. The method according to claim 1 , wherein the concentration of formamide is less than or equal to 20% v/v.

23. The method according to claim 1 , wherein the concentration of formamide is 10% to 15% v/v.

24. The method according to claim 1 , wherein the concentration of formamide is 10% to 20% v/v.

25. The method according to claim 1 , wherein the concentration of formamide is 15% to 20% v/v.

26. The method according to claim 1 , wherein the salt is NaCl.

27. The method according to claim 26 , wherein the NaCl is present at a concentration of 400 to 700 mM.

28. The method according to claim 26 , wherein the NaCl is present at a concentration of about 600 mM.

29. The method according to claim 1 , further comprising at least one additional component selected from the group consisting of: buffering agents, chelating agents, detergents, blocking agents, and combinations thereof.

30. The method according to claim 27 , wherein the at least one additional component is a blocking agent selected from the group consisting of: total human DNA, COT1 DNA, blocking PNA, herring sperm DNA, salmon sperm DNA, and calf thymus DNA.

31. The method according to claim 1 , wherein the blocking agent is present at a concentration of 0.01 to 10 ug/uL.

32. The method according to claim 1 , wherein the accelerating agent is dextran sulfate and, wherein the dextran sulfate is present at a concentration of about 20% to about 40% w/v.

33. The method according to claim 1 , wherein the accelerating agent is dextran sulfate and wherein the dextran sulfate is present at a concentration of about 20% w/v.

34. A method of hybridizing nucleic acid sequences comprising:

providing a first nucleic acid sequence,

providing a second nucleic acid sequence,

providing a hybridization composition comprising formamide, and

combining the first and the second nucleic acid sequence and the hybridization composition for at least a time period sufficient to hybridize the first and second nucleic acid sequences, wherein the time period is less than 4 hours,

wherein the concentration of formamide is 10% to 25% v/v;

wherein the hybridization composition further comprises 15% to 80% of an accelerating agent and 400 mM to 1200 mM of a salt.