Mass spectrometry (mass spec) is concerned with the separation of matter according to atomic and molecular mass.
High throughput mass spectrometry, using the most sophisticated instrumentation (matrix-assisted laser desorption ionisation time-of-flight – MALDI-TOF/TOF or electrospray ionisation MS/MS – LC-MS/MS) is exclusively used:
For protein sequencing by tandem MS (MALDI-TOF/TOF or LC-MS/MS), protein samples are enzymatically digested to produce fragmented peptides. Spectra are obtained for the major peptide ions in MS mode and sequence data is obtained in MS/MS mode. These spectra are then compared to databases to provide hits that identify matching or similar sequences. The end result is positive verification of protein identity.
Analysis by MALDI-TOF/TOF (PMF+MS/MS) is optimal for Coomassie stained gels and 2D gel spots.
Analysis by electrospray (LC-MS/MS) mass spectrometry is optimal for gel bands containing two or more proteins or for low abundant samples.
Fast and accurate results at affordable prices.
Request Form: Protein Identification by Mass Spectrometry
Tandem mass spectrometry (MALDI-TOF/TOF or LC-MS/MS) is used to determine the primary sequence of proteins that are not present in currently available databases. Crude extracts or pure samples can be analysed and our expert operators use the latest software to interpret the MS/MS spectra and derive your sequence.
Request Form: De Novo Peptide Sequencing
For more information please refer to PI publication:
Bringans S.D., Kendrick T., Lui J., and Lipscombe R.J. (2008) A comparative study of the accuracy of several de novo sequencing software packages for datasets derived by matrix-assisted laser desorption/ionisation and electrospray. Rapid Commun. Mass Spectrom. 22(21): 3450-4.
Peptide mass fingerprinting for protein identification by mass spectrometry is now superseded by mass spectrometry sequencing (PMF+MS/MS).
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Suitable for pure samples, this service provides a molecular mass for the protein or peptide of interest.
Samples are processed intact (no enzyme digestion). Depending on the size of the molecule and mass accuracy required MALDI-TOF MS and/or LC/MS is used.
For a RMM <6000amu MALDI-TOF is recommended, and >6000amu LC/MS is preferred.
Request Form: Protein Mass Analysis