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Integrated Structural Biology Grenoble

Contact person(s) related to this article / Caroline Mas



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 their native state and without the need for labels in one measurement.

Mass photometry builds on the principles of interference reflection microscopy and interferometric scattering microscopy.
The group of Prof. Kukura at Oxford University has demonstrated that the amount of light scattered by single molecules can be reliably detected and that it is directly correlated with molecular mass.

The principle of mass photometry
The light scattered by a molecule attached to the measurement interface interferes with light reflected at that interface. The interference contrast scales linearly with mass.

The light scattered by a particle scales linearly with particle volume and refractive index. As the optical properties and density of proteins vary only by a few percent, their scattering signal is directly proportional to their sequence mass – making it possible to weigh single molecules with light. The correlation of scattering signal with mass holds true for a variety of biomolecules (glycoproteins, nucleic acids or lipids), making mass photometry a universal analysis tool for biomolecules in solution.

Mass photometry measures the molecular mass of proteins and protein assemblies in solution
Via calibration, mass photometry enables the mass measurement of unknowns with high accuracy.

Young et al. (2018) Science 360, 423–427
Sonn-Segev et al. (2020) Nat Commun 11, 1772


  • Sample characterisation
  • Protein oligomerization
  • Biomolecular interactions
  • Macromolecular assemblies

Key words

molecular mass, single molecule, low amount of sample


Manager: Caroline Mas
Office: CIBB room 017
Platform: EMBL room 152

Spectific equipement

Reyfen One MP
What does a Mass Photometry experiment look like?


Sample concentration: nM range
Quantity: few microL

MP one - Key Specifications

Access mode

Users must read the conditions of use of the instruments as well as of the management of the services provided:

Access mode
General Conditions

It is mandatory to be trained by the platform manager before using this instrument.
The first use will be done with the assistance of the manager.
After demonstrating his autonomy, the user will be able to use the instrument in complete independence.

The platform is accessible to local PSB researchers, external academics (Instruct) and industrials.
The platform manager will provide assistance for:

  • experimental design
  • data collection
  • samples considerations
  • data analysis

Contact the platform manager to arrange a meeting.

Scientific collaboration: projects in which the biophysics platform manager is strongly involved. In this case, experiments are designed, performed and analyzed in tandem between the scientific responsible and the applicant.


Academics: Participation to the maintenance fees
Industrials: Please contact us for cost information.


The MP one is located at the EMBL, laboratory 152, 1st Floor (Map Here)

How to access the instrument

As mentioned above, it is mandatory to be trained by the platform manager before using this instrument. After demonstrating his autonomy, the user will be able to use the instrument in complete independence.
Booking is allocated for 1/2 day.
To make a booking request, submit the REQUEST FORM HERE
Please consult the booking calendar to ensure availability.

Mass Photometer Booking Calendar

The user agrees to promote the obtained results by mentioning the platform in the acknowledgements in case of publication or scientific communication and to communicate the reference of the article to the responsible for the platform.

  • Service / Providing access mode: Acknowledgements in publications and oral presentations
  • Collaboration: Co-authors in publications and oral presentations.

Acknowledgements in publications:
Please find below the sentence that has to be written in all publications based on our UAR platforms:
"This work used the platforms of the Grenoble Instruct-ERIC center (ISBG ; UAR 3518 CNRS-CEA-UGA-EMBL) within the Grenoble Partnership for Structural Biology (PSB), supported by FRISBI (ANR-10-INBS-0005-02) and GRAL, financed within the University Grenoble Alpes graduate school (Ecoles Universitaires de Recherche) CBH-EUR-GS (ANR-17-EURE-0003). We thank Caroline Mas for assistance and/or access to the biophysics platform."