Claims
- 1. A method for identifying and quantifying polypeptides in a sample, comprising the steps of:
(a) labeling peptides in a polypeptide sample with an isotope tag; (b) adding a plurality of peptide standards to said polypeptide sample, wherein said peptide standards are labeled with an isotopically distinct version of said isotope tag; (c) resolving said labeled sample and standard peptides into a plurality of fractions; (d) analyzing said resolved fractions using mass spectrometry; (e) identifying an isotope-tagged sample peptide in an analyzed fraction; and (f) determining the amount of the identified isotope-tagged sample peptide in said analyzed fraction by comparison to the amount of isotope tagged standard peptide in the same fraction.
- 2. The method of claim 1, wherein said plurality of fractions is deposited onto a mass spectrometry sample plate.
- 3. The method of claim 1, wherein a known absolute amount of each of said peptide standards is added to said polypeptide sample.
- 4. The method of claim 1, wherein said polypeptide sample is cleaved with a protease.
- 5. The method of claim 4, wherein said protease is trypsin.
- 6. The method of claim 1, wherein said sample is derived from a body fluid selected from the group consisting of blood, plasma, cerebrospinal fluid, urine, saliva, seminal plasma, and pancreatic juice.
- 7. The method of claim 6, wherein said sample is derived from serum.
- 8. A method for quantifying polypeptides in a sample, comprising the steps of:
(a) labeling peptides in a polypeptide sample with an isotope tag; (b) adding a known absolute amount of a plurality of peptide standards to said polypeptide sample, wherein said peptide standards are labeled with an isotopically distinct version of said isotope tag; (c) resolving said labeled sample and standard peptides into a plurality of fractions; (d) analyzing said resolved fractions using mass spectrometry; (e) identifying an isotope-tagged sample peptide in an analyzed fraction; and (f) determining the amount of the identified isotope-tagged sample peptide in said analyzed fraction by comparison to the amount of isotope tagged standard peptide in the same fraction.
- 9. The method of claim 8, wherein said plurality of fractions is deposited onto a mass spectrometry sample plate.
- 10. The method of claim 8, wherein said polypeptide sample is cleaved with a protease.
- 11. The method of claim 10, wherein said protease is trypsin.
- 12. The method of claim 8, wherein said sample is derived from a body fluid selected from the group consisting of blood, plasma, cerebrospinal fluid, urine, saliva, seminal plasma, and pancreatic juice.
- 13. The method of claim 12, wherein said sample is derived from serum.
- 14. A method for identifying and quantifying splice isoforms of polypeptides in a sample, comprising the steps of:
(a) labeling peptides in a polypeptide sample with an isotope tag; (b) adding a plurality of peptide standards to said polypeptide sample, wherein said peptide standards are labeled with an isotopically distinct version of said isotope tag and wherein said plurality of peptide standards comprises at least one peptide corresponding to a common amino acid sequence of a splice isoform of a polypeptide and at least one peptide corresponding to an amino acid sequence that differs between two splice isoforms of said polypeptide; (c) resolving said labeled sample and standard peptides into a plurality of fractions; (d) analyzing said resolved fractions using mass spectrometry; (e) identifying an isotope-tagged sample peptide in an analyzed fraction; and (f) determining the amount of the identified isotope-tagged sample peptide in said analyzed fraction by comparison to the amount of isotope tagged standard peptide in the same fraction.
- 15. The method of claim 14, wherein said plurality of fractions is deposited onto a mass spectrometry sample plate.
- 16. The method of claim 14, wherein a known absolute amount of each of said peptide standards is added to said polypeptide sample.
- 17. The method of claim 14, wherein said polypeptide sample is cleaved with a protease.
- 18. The method of claim 17, wherein said protease is trypsin.
- 19. The method of claim 14, wherein said sample is derived from a body fluid selected from the group consisting of blood, plasma, cerebrospinal fluid, urine, saliva, seminal plasma, and pancreatic juice.
- 20. The method of claim 19, wherein said sample is derived from serum.
Parent Case Info
[0001] This application claims the benefit of priority of U.S. Provisional application serial No. 60/385,941 filed Jun. 4, 2002, the entire contents of which is incorporated herein by reference.
Government Interests
[0002] This invention was made with government support under grant number CA 84698 awarded by the National Cancer Institute. The government has certain rights in the invention.
Provisional Applications (1)
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Number |
Date |
Country |
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60385941 |
Jun 2002 |
US |