Peptide Molecular Weight Determination

Relative molecular mass or molecular weight of a molecule is calculated by the relative atomic masses of each constituent element. Together with HPLC purity, confirmation of the molecular weight of a synthetic peptide provides preliminary evidence on the success of peptide synthesis. In mass spectrometry, the molecular mass of a larger molecule such as a peptide is usually calculated based on the average molecular mass which is the average of the isotopic masses weighted by the isotopic abundances.

We determine the molecular weight of peptides by different mass spectrometric approaches. We use different ionizations (e.g. ESI and MALDI) as well as various detection methods such as TOF, ion trap or quadrupole, depending on the properties and associated detectability of a peptide.

Material requisition: > 150 µg/sample

Time needed: 1-2 days