Protein AQUA, a powerful breakthrough technology, enables ultrasensitive protein quantitation using stable isotope labelled peptides and Mass Spectrometry. Custom AQUA peptides are synthesized using fully labelled 98 atom 13C and 98 atom 15N enriched amino acids (one labelled 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 are available in small (5 x 1 nmol) package sizes to enable convenient sample preparation and provide an appropriate peptide amount. Unlike alternative quantitative methods, Protein-AQUA sensitivity is virtually unlimited.
"The vastly superior sensitivity of mass spectrometry over any other method currently available in conjunction with AQUA-based methods will enable quantitation of proteins at levels of sensitivity previously considered unattainable," said Michael Hadjisavas, global proteomics business manager for Sigma-Aldrich.
Mass spectrometry allows many proteins to be identified without the need for full de novo sequencing, there are still many proteins that cannot be identified through this approach due to the volume and complexity of the proteins.
One reason for this may be the inability of many peptides within a mixture to ionise efficiently, a problem that is exacerbated for less abundant molecules.
This method was developed by Dr Steve Gygi and colleagues at Harvard Medical School and their study, entitled, "Dual inhibition of sister chromatid separation at metaphase, Cell 2001, (Dec 14, 107: 715-726) is the subject of both US and PCT patent applications.