Molecular Weight Determination

Molecular weight is a fundamental physicochemical property parameter of organic compounds, generally referring to the relative molecular mass, which is the sum of the relative atomic masses of all atoms in the chemical formula of the compound. The correctness of molecular weight often represents the correctness of the structure of the measured organic compound or biological macromolecule. Molecular weight is a primary parameter in the identification of polypeptides, proteins, etc., and is also important data for the approval of genetic engineering products.

Molecular Weight Determination

There are many methods for determining protein molecular weight, and the commonly used ones include viscosity method, gel permeation chromatography, SDS-PAGE method, light scattering method, and mass spectrometry. Among them, mass spectrometry mainly includes electrospray ionization (ESI) mass spectrometry and matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. Compared to other methods, mass spectrometry for identifying protein molecular weight consumes less sample and has higher sensitivity, resolution, and accuracy, which is beneficial for analyzing complex mixture samples. In addition, mass spectrometry can also be used to determine the molecular weight of protein complexes and protein-small molecule complexes.