This service provides an accurate determination of the molecular weight of a protein sample up to 150 kiloDalton in mass. It can be done on the intact protein or subunits/domain level. Electrospray ionization requires high purity samples but can provide the highest resolution possible. The sample is detected while having multiple charge states (as shown in the figure below), but by using deconvolution software the exact mass of the intact molecule can be calculated with a high degree of accuracy.
CovalX utilizes the latest mass spectrometry instrumentation and software for electrospray (ESI) analysis. We have access to a full range of high-resolution electrospray instruments including the latest Orbitrap instrumentation.
Typically we request the highest purity and concentration possible for each sample, but sample prep can be customized to a customer's needs as well. All samples are injected using liquid chromatography separation prior to mass spec ionization. Optimization of instrumental operating parameters for protein/peptide analysis is also required for providing proper data.