Mass Photometry

Mass Photometry is offered using the Refeyn One system. This applies the principle of interference reflection microscopy and interferometric scattering microscopy to quantify light scattered by a single molecule on a glass surface. The amount of light scattered by each molecule is directly correlated to its molecular mass.

Based on the above principle, the Refeyn One can monitor protein-protein interactions at a single-molecule level with high-sensitivity and can at the same time determine molecular weight of proteins and protein complexes with a high dynamic range and great accuracy.

The mass photometer is an ideal tool for quality control in the protein structural analysis workflow, as it can assess the molecular mass and the oligomerisation status of a sample in one measurement.

What are the sample requirements?

  • Sample concentration and volume: The amount of protein needed for an analysis is very small, between 5 µl to 20 µl  of protein solution needed at a nano-molar concentration range ( e.g 100 nM). After the initial set up, measurement generally takes one minute, though sometimes requires slightly longer.
  • Mass range: 40 kDa – 5 MDa
  • Concentration range: 100 pM – 100 nM (particle concentration)
  • Buffer requirements: Centrifuge buffers (0.22 microns or 0.11 microns) prior to the measurements. Avoid buffers with a high percentage of glycerol.

What other specific considerations are relevant?

  • In the most common measurement mode, the protein solution is diluted in a drop of buffer, so it is recommend to bring a protein sample with at least 1 uM concentration.
  • Membrane proteins could be measured upon consideration. For further information, please read the following publication:

Partners offering this technique

MOSBRI reference partner site for this technique:

Other partners: