The Ultimate Method for Biomarker Quantitation…

Protein-AQUA™ is a powerful, enabling technology that facilitates focused, quantitative studies of not only specific protein expression, but specific amino acid modification as well. The protein AQUA strategy, originally presented in 2003 by Dr. Steve Gygi and his team, enables absolute protein quantitative using stable isotope labeled peptides and HPLC-MS.

Protein-AQUA™ is based on a common principle: the use of a labeled molecule as an internal standard. By applying this technique to protein and peptide analysis, Gygi's team has advanced the abilities of protein researchers to study complex biological samples quantitatively and has provided a valuable new tool for Proteomics!

To meet the specific requirements of AQUA experimentation, Sigma has developed a specialized custom peptide offering. Custom AQUA Peptides are synthesized using fully labeled 98 atom% ¹³C and 98 atom% ¹⁵N enriched amino acids (one labeled amino acid per peptide) and are stringently tested to ensure high purity (HPLC), accurate molecular weight (MALDI-TOF MS), and specific peptide content.

Custom AQUA Peptides

• 95% peptide purity by reverse-phase HPLC
• 98 atom% ¹³C and 98 atom% ¹⁵N isotopically labeled amino acid incorporation
• Confirmed molecular weight by MALDI-TOF Mass Spectrometry
• Confirmed peptide content
• Peptides supplied as Trifluoroacetate salt (ammonia acetate salt form also available)
• Phosphorylated amino acids available

Protein-AQUA™

In June 2003, Dr. Steve Gygi and his team presented a strategy for absolute protein quantitation using stable isotope labeled peptides and HPLC-MS.1 This technique, Protein-AQUA™, is based on a common principle: the use of a labeled molecule as an internal standard. Protein-AQUA™ has often been used in MS analysis of small molecules, but by applying it to protein and peptide analysis, Gygi’s team has advanced the abilities of protein researchers to study complex biological samples quantitatively and have provided a valuable new tool for Proteomics.