Get Proteomics Sample Submission Form

Mass spectrometry is an analytical tool useful for measuring the mass-to-charge ratio (m/z) of one or more molecules present in a sample. These measurements can often be used to calculate the exact molecular weight of the sample components as well.

Mass spectrometers do one thing—they measure mass. In proteomics, the mass gives information on the protein identity, its chemical modifications, and its structure. Every mass spectrometer has three main components: a source, an analyzer, and a detector.

Digestion of protein samples with Trypsin is widely used. Complete digestion of protein samples (10 µg) is achieved by incubating at 37 ℃ with trypsin to protein ratio of 1:20 for 4 hr with gentle agitation. Adding more trypsin results in trypsin autolysis and additional peaks are observed during mass spec analysis.

The mass spectrometric detection of a targeted peptide relies on the accurate mass and exact sequence of the peptide of interest, thus, when combined with effective sample preparation method, the technique is highly specific and capable of quantifying the corresponding protein.

Mass spectrometers do one thing—they measure mass. In proteomics, the mass gives information on the protein identity, its chemical modifications, and its structure. Every mass spectrometer has three main components: a source, an analyzer, and a detector.

Therefore, typical sample preparation processes for bottom-up proteomics usually include lysis/homogenization, protein extraction/precipitation, reduction, alkylation, enzymatic digestion, fractionation, and desalting (Figure 1).

The two primary methods used for the ionization of protein in mass spectrometry are electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI). These ionization techniques are used in conjunction with mass analyzers such as tandem mass spectrometry.