Mass Spectrometry

AQUA™ Peptides

Developed in collaboration with the Protein Quantitation Consortium, Sigma's AQUA Peptides enable accurate, efficient mass spectrometric quantitation of protein biomarkers.

  • Focus your analysis on significant protein biomarkers
  • Accurately quantitate low abundance proteins
  • Eliminate costly, time consuming stable isotope labeling steps
  • Measure site-specific phosphorylation states
  • Validate gene silencing at the protein level

View additional information on the Protein AQUA Strategy and Protein AQUA Applications and Protein AQUA References.

This method was developed by Dr. Steve Gygi and colleagues at Harvard Medical School [Stemmann O., Zou H., Gerber S. A., Gygi S. P., Kirschner M. W.; Dual inhibition of sister chromatid separation at metaphase, Cell 2001, Dec 14, 107: 715-726]. Limited use of this method is permitted under a licensing arrangement with Harvard Medical School.


Sigma is pleased to announce the launch of its AQUA Peptide Library. Select from a library of over 300 readily available AQUA Peptides for even greater convenience and value.

Browse The AQUA Peptide Library
Choose from the three methods below:


Download Sequences and Protein IDs
Want associated protein information?


AQUA Library
(2.19 Mb PDF)
AQUA Library
(1.68 Mb PDF)

View by Sequence and Product Number
Want to browse the AQUA Peptide Library catalog listings?

View the online catalog of AQUA Library Peptides

Can't find your AQUA of interest in the library?
Take advantage of our Custom AQUA Peptide Design Tool page.

Custom Peptides and Custom AQUA™ Peptides

Sigma offers high-purity custom peptides.  Our custom peptides are stringently tested to ensure high purity (HPLC), accurate molecular weight (ESI-MS), and specific peptide content.  

  • Custom peptides are available without stable isotope labeling.
  • To meet the specific demands of AQUA experimentation, custom AQUA™ peptides are available using fully labeled 98 atom% 13C and 98 atom% 15N enriched amino acids, with one labeled amino acid per peptide.
  • For both unlabeled and isotopically labeled custom peptides, we offer the following modifications:  phosphorylation (Ser, Thr, Tyr), carboxymethylation (Cys), carbamidomethylation (Cys), hydroxyproline, and N-terminal biotin.
  • Custom peptides and custom AQUA™ peptides up to 30 amino acids long can be synthesized.
  • Standard synthesis amount is 5 x 1 nmol (quantified using AAA).

AQUA Peptide References

  1. Guenther, J.F., et al., Phosphorylation of soybean nodulin 26 on serine 262 enhances water permeability and is regulated developmentally and by osmotic signals. Plant Cell, 15(4), 981-991 (2003). Abstract
  2. Brun, V., et al., Isotope-labeled Protein Standards: Toward Absolute Quantitative Proteomics. Mol. Cell. Proteomics, 6(12), 2139-2149 (2007). Abstract
  3. Li, N., et al., Absolute Difference of Hepatobiliary Transporter Multidrug Resistance-Associated Protein (MRP2/Mrp2) in Liver Tissues and Isolated Hepatocytes from Rat, Dog, Monkey, and Human. Drug. Metab. Dispos., 37(1), 66-73 (2009). Abstract
  4. Velez, J.C.Q., et al., Angiotensin I Is Largely Converted to Angiotensin (1-7) and Angiotensin (2-10) by Isolated Rat Glomeruli.  Hypertension, 53, 790-797 (2009). Abstract
  5. Singh, S., et al., FLEXIQuant: A novel tool for the absolute quantification of proteins, and the simultaneous identification and quantification of potentially modified peptides. J. Proteome Res., 8(5), 2201-2210 (2009). Abstract
  6. Zhou, Y., et al., Calmodulin Mediates the Ca2+-Dependent Regulation of Cx44 Gap Junctions. Biophys. J., 96(7), 2832-2848 (2009). Abstract
  7. Li, H., et al., Proximal glycans outside of the epitopes regulate the presentation of HIV-1 envelope gp120 helper epitopes. J. Immunol., 182(10), 6369-6378 (2009). Abstract
  8. Le Bihan, T., et al., Quantitative analysis of low-abundance peptides in HeLa cell cytoplasm by targeted liquid chromatography/mass spectrometry and stable isotope dilution: emphasising the distinction between peptide detection and peptide identification. Rapid Commun. Mass Spectrom., 24(7), 1093-1104 (2010). Abstract
  9. Rosario, M., et al., Novel Recombinant Mycobacterium bovis BCG, Ovine Atadenovirus, and Modified Vaccinia Virus Ankara Vaccines Combine To Induce Robust Human Immunodeficiency Virus-Specific CD4 and CD8 T-Cell Responses in Rhesus Macaques. J. Virol., 84(12), 5898-5908 (2010). Abstract
  10. Kettenbach, A.N., et al., Absolute quantification of protein and post-translational modification abundance with stable isotope–labeled synthetic peptides. Nat. Protoc., 6(2), 175-186 (2011). Abstract
  11. Santhoskumar, P., et al., αA-Crystallin Peptide 66SDRDKFVIFLDVKHF80 Accumulating in Aging Lens Impairs the Function of α-Crystallin and Induces Lens Protein Aggregation. PLoS One, 6(4), e19291 (2011). Abstract
  12. Kroot, J.J.C., et al., Second Round Robin for plasma hepcidin methods: First steps toward harmonization.  Am. J. Hematol., 87(10), 977-983 (2012). Abstract
  13. Coppinger, J.A., et al. A Chaperone Trap Contributes to the Onset of Cystic Fibrosis. PLoS One, 7(5), e37682 (2012). Abstract
  14. Sato, Y., et al., Simultaneous Absolute Protein Quantification of Carboxylesterases 1 and 2 in Human Liver Tissue Fractions using Liquid Chromatography-Tandem Mass Spectrometry. Drug Metab Dispos., 40(7), 1389-1396 (2012). Abstract
  15. Stevenson, S.E., et al., Environmental Effects on Allergen Levels in Commercially Grown Non-Genetically Modified Soybeans: Assessing Variation Across North America. Front. Plant Sci., 3, 196 (2012). Abstract
  16. van de Steeg, E., et al., Drug-Drug Interactions between Rosuvastatin and Oral Antidiabetic Drugs Occurring at the Level of OATP1B1.  Drug. Metab. Dispos., 41(3), 592-601 (2013). Abstract
  17. Schwacke, J.H., et al., Network modeling reveals steps in angiotensin peptide processing. Hypertension, 61(3), 690-700 (2013). Abstract
  18. Wu, S., et al., CAND1 controls in vivo dynamics of the cullin 1-RING ubiquitin ligase repertoire. Nat. Commun., 4, 1642-1650 (2013). Abstract
  19. Stecker, K., et al., Phosphoproteomic Analyses Reveal Early Signaling Events in the Osmotic Stress Response. Plant Physiol., 165(3), 1171-1187 (2014).

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