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Stanford University Mass Spectrometry Vincent Coates Foundation
Vincent Coates Foundation

Intact Protein Characterization

Determination of the intact molecular weight of a highly pure protein.

Intact protein characterization is performed on samples in solution using electrospray ionization mass spectrometry (ESI-MS).  Because the mass spectrometer measures the component’s mass-to-charge ratio, and electrospray ionization of proteins can generate ions with multiple charges, proteins of molecular weight up to 150kDa have been analyzed successfully.

Concentration & Volume

  • For routine intact mass analysis, the minimum amount of protein required depends on the MW of the peptide or protein.
  • Good results have been obtained with 25 pmol at 5 kD, 100 pmol at 20 kD, 200 pmol at 40 kD, and 500 pmol at 60 kD.
  • Sample concentration should be such that the appropriate amount of protein is contained in 20-25 uL