The 6x5 LC-MS/MS Peptide Reference Mixture and Software Analysis Tool
- Interrogate LC performance through six peptides of varying hydrophobicity
- Examine MS performance through five isotopologues of each peptide
Summary
Data generated by scientific instruments and decisions based on that data depend of the instruments performing consistently. Users monitor and record parameters such as LC retention time, peak width and height while also monitoring MS parameters including accuracy, resolution, signal to noise, sensitivity (LOQ and LOD) and dynamic range. Oftentimes, no single standard can serve both purposes. To this end, we have developed the 6 x 5 LC-MS/MS Peptide Reference Mixture. The mixture is composed of six sets of five isotopologues (incorporating the heavy isotopes 13C and 15N) of the same peptide sequence. Separation of the six sets will test the LC parameters of retention time, peak width and peak height. Deconvolution of the six peaks into five isotopologues each will assess accuracy and resolution of the MS instrument. To further challenge the MS instrument, the five isotopologues are present in 10-fold differences of molar abundance to assess sensitivity and dynamic range. For example, if the heaviest peptide is loaded at 1pmol, the next is 100fmol all the way down 100amol. So, in one single run, the 6 x 5 LC-MS/MS Peptide reference Mixture will allow you to assess both LC and MS parameters. Monitoring these parameters over time can alert you to changes in your system. To assist you in monitoring your instruments, we will provide the 6 x 5 LC-MS/MS Peptide Mixture Analysis Software or PReMiS™. PreMiS™ will be a free download and will accept raw data files from Thermo or AB Sciex. Data files from other instruments require only conversion to .mzML format. The software will produce a tabular report of calculated instrument parameters, graphical analysis of linearity curves and possibly more important, provide a history of instrument performance. Other features allow you to compare different instruments in your laboratory or performance of a collaborators instrument running the same reference mix.
Speaker
Mike Rosenblatt, PhD
R&D Group Leader, Mass Spec
Mike is the leader of the Mass Spec Reagents group at Promega Corporation, based in Madison, WI. He received his B.S. degree from Towson University and PhD from the University of Illinois at Urbana-Champaign. After completing an NIH post-doctoral fellowship at the University of Pennsylvania, he founded the Proteomics Core facility at the Children’s Hospital of Philadelphia. Prior to joining Promega he worked with Thermo-Fisher Scientific (Pierce Products) where he was a Senior Scientist focusing on the development of reagents for the preparation of samples for biological mass spectrometry.