Chemical compositions and methods of using same

1. A method comprising the steps of:

(1) hybridizing a first probe to a target nucleic acid in a sample,

wherein the first probe comprises a target binding domain linked to a barcode domain,

wherein the target binding domain comprises at least eight nucleotides and is capable of binding a target nucleic acid, wherein at least six nucleotides in the target binding domain are capable of identifying a target nucleic acid molecule and wherein at least two nucleotides in the target binding domain do not identify the target nucleic acid molecule;

wherein the barcode domain comprises at least one attachment position, each attachment position comprising at least one attachment region comprising at least one nucleic acid sequence capable of being bound by a complementary nucleic acid molecule, wherein the nucleic acid sequence of the at least one attachment position determines the identity of the target nucleic acid that is bound by the target binding domain;

(2) binding a complementary nucleic acid molecule including a detectable label to the first attachment position of the barcode domain of the probe;

(3) detecting the detectable label of the bound complementary nucleic acid molecule;

(4) repeating steps (2) to (3) until each attachment position in the barcode domain of the probe has been bound by a complementary nucleic acid molecule including a detectable label, and the detectable label of the bound complementary nucleic acid molecule has been detected;

(5) de-hybridizing the first probe hybridized to the target nucleic acid in step (1);

(6) hybridizing a second probe to the target nucleic acid in the sample,

wherein the second probe comprises a target binding domain linked to a barcode domain,

wherein the target binding domain comprises at least eight nucleotides and is capable of binding a target nucleic acid, wherein at least six nucleotides in the target binding domain are capable of identifying a target nucleic acid molecule and wherein at least two nucleotides in the target binding domain do not identify the target nucleic acid molecule;

wherein the barcode domain comprises at least one attachment position, each attachment position comprising at least one attachment region comprising at least one nucleic acid sequence capable of being bound by a complementary nucleic acid molecule, wherein the nucleic acid sequence of the at least one attachment position determines the identity of the target nucleic acid that is bound by the target binding domain;

(7) binding a complementary nucleic acid molecule including a detectable label to a first attachment position of the barcode domain of the second probe;

(8) detecting the detectable label of the bound complementary nucleic acid molecule; and

(9) repeating steps (7) to (8) until each attachment position in the barcode domain of the second probe has been bound by a complementary nucleic acid molecule including a detectable label, and the detectable label of the bound complementary nucleic acid molecule has been detected.

2. The method of claim 1 , wherein the method further comprises identifying the target nucleic acid that was hybridized to the target binding domain of the first probe and the second probe based on the detectable labels that were detected in steps (3) and (8).

3. The method of claim 1 , further comprising the steps of:

(10) de-hybridizing the second probe hybridized to the target nucleic acid in step (5);

(11) hybridizing a third probe to the target nucleic acid in the sample,

wherein the third probe comprises a target binding domain linked to a barcode domain,

wherein the target binding domain comprises at least eight nucleotides and is capable of binding a target nucleic acid, wherein at least six nucleotides in the target binding domain are capable of identifying a target nucleic acid molecule and wherein at least two nucleotides in the target binding domain do not identify the target nucleic acid molecule;

wherein the barcode domain comprises at least one attachment position, each attachment position comprising at least one attachment region comprising at least one nucleic acid sequence capable of being bound by a complementary nucleic acid molecule, wherein the nucleic acid sequence of the at least one attachment position determines the identity of the target nucleic acid that is bound by the target binding domain;

(12) binding a complementary nucleic acid molecule including a detectable label to a first attachment position of the barcode domain of the third probe;

(13) detecting the detectable label of the bound complementary nucleic acid molecule;

(14) repeating steps (12) to (13) until each attachment position in the barcode domain of the third probe has been bound by a complementary nucleic acid molecule including a detectable label, and the detectable label of the bound complementary nucleic acid molecule has been detected.

4. The method of claim 3 , wherein the method further comprises identifying the target nucleic acid that was hybridized to the target binding domain of the first probe, the second probe and the third probe based on the detectable labels that were detected in steps (3), (8) and (13).

5. The method of claim 1 , wherein the sample is a tissue sample.

6. The method of claim 1 , wherein the target binding domain comprises at least ten nucleotides.

7. The method of claim 1 , wherein the barcode domain comprises a single-stranded DNA.

8. The method of claim 1 , wherein each attachment position in the barcode domain comprises one attachment region.

9. The method of claim 1 , wherein the at least two nucleotides in the target binding domain that do not identify the target nucleic acid molecule follow the at least six nucleotides in the target binding domain that identify the target nucleic acid molecule.

10. The method of claim 1 , wherein the at least six nucleotides in the target binding domain that are capable of identifying the target nucleic acid molecule are complementary to a portion of the target nucleic acid molecule.

11. The method of claim 1 , wherein the at least two nucleotides in the target binding domain that are not capable of identifying a target nucleic acid molecule are not complementary to a portion of the target nucleic acid molecule.

12. The method of claim 1 , wherein the barcode domain comprises one attachment position.

13. The method of claim 1 , wherein each attachment position comprises between 8 nucleotides and 20 nucleotides.

14. The method of claim 1 , wherein each attachment position comprises about 20 nucleotides.

15. The method of claim 1 , wherein the detectable label is a fluorescent label.

16. A method comprising the steps of:

(1) hybridizing a first population of probes to a plurality of target nucleic acids in a sample,

wherein the probes in the first population of probes comprise a target binding domain linked to a barcode domain,

wherein the target binding domain comprises at least eight nucleotides and is capable of binding a target nucleic acid, wherein at least six nucleotides in the target binding domain are capable of identifying a target nucleic acid molecule and wherein at least two nucleotides in the target binding domain do not identify the target nucleic acid molecule;

wherein the barcode domain comprises at least one attachment position, each attachment position comprising at least one attachment region comprising at least one nucleic acid sequence capable of being bound by a complementary nucleic acid molecule, wherein the nucleic acid sequence of the at least one attachment position determines the identity of the target nucleic acid that is bound by the target binding domain;

(2) binding a complementary nucleic acid molecule including a detectable label to a first attachment position of the barcode domains of the hybridized probes;

(3) detecting the detectable label of the bound complementary nucleic acid molecules;

(4) repeating steps (2) to (3) until each attachment position in the barcode domains of the hybridized probes have been bound by a complementary nucleic acid molecule including a detectable label, and the detectable label of the bound complementary nucleic acid molecule has been detected;

(5) de-hybridizing the first population of probes hybridized to the plurality of target nucleic acids in step (1);

(6) hybridizing a second population of probes to the plurality of target nucleic acids in the sample

wherein the probes in the second population of probes comprise a target binding domain linked to a barcode domain,

wherein the target binding domain comprises at least eight nucleotides and is capable of binding a target nucleic acid, wherein at least six nucleotides in the target binding domain are capable of identifying a target nucleic acid molecule and wherein at least two nucleotides in the target binding domain do not identify the target nucleic acid molecule;

wherein the barcode domain comprises at least one attachment position, each attachment position comprising at least one attachment region comprising at least one nucleic acid sequence capable of being bound by a complementary nucleic acid molecule, wherein the nucleic acid sequence of the at least one attachment position determines the identity of the target nucleic acid that is bound by the target binding domain;

(7) binding a complementary nucleic acid molecule including a detectable label to a first attachment position of the barcode domains of the probes hybridized in step (6);

(8) detecting the detectable label of the bound complementary nucleic acid molecules;

(9) repeating steps (7) to (8) until each attachment position in the barcode domains of the hybridized probes have been bound by a complementary nucleic acid molecule including a detectable label, and the detectable label of the bound complementary nucleic acid molecule has been detected.

17. The method of claim 16 , wherein the method further comprises identifying the target nucleic acids that were hybridized to the target binding domains of the probes in the first population of probes and the probes in the second population of probes based on the detectable labels that were detected in steps (3) and (8).

18. The method of claim 16 , wherein the sample is a tissue sample.

19. The method of claim 16 , wherein the target binding domain comprises at least ten nucleotides.

20. The method of claim 16 , wherein the barcode domain comprises a single-stranded DNA.

21. The method of claim 16 , wherein each attachment position in the barcode domain comprises one attachment region.

22. The method of claim 16 , wherein the at least two nucleotides in the target binding domain that do not identify the target nucleic acid molecule follow the at least six nucleotides in the target binding domain that identify the target nucleic acid molecule.

23. The method of claim 16 , wherein the at least six nucleotides in the target binding domain that are capable of identifying the target nucleic acid molecule are complementary to a portion of the target nucleic acid molecule.

24. The method of claim 16 , wherein the at least two nucleotides in the target binding domain that are not capable of identifying a target nucleic acid molecule are not complementary to a portion of the target nucleic acid molecule.

25. The probe of claim 16 , wherein the barcode domain comprises one attachment position.

26. The method of claim 16 , wherein each attachment position comprises between 8 nucleotides and 20 nucleotides.

27. The method of claim 16 , wherein each attachment position comprises about 20 nucleotides.

28. The method of claim 16 , wherein the detectable label is a fluorescent label.