Refeyn installs its 500th mass photometry system

Refeyn, a pioneer in mass photometry technology, has announced the installation of the 500th system based on its novel single-particle bioanalytical technology within just seven years of its spinout from the University of Oxford. The company’s TwoMP mass photometer and MassFluidix HC system were installed for the Ploug Group at the University of Copenhagen’s Biotech Research & Innovation Centre, in order to further studies of proteins involved in disease-relevant pathways.

Refeyn’s technology enables the label-free characterisation of single biomolecules and viral particles in solution in their native state. The Ploug Group is using mass photometry to study intravascular lipid metabolism, already citing it in a new research article investigating the regulation of lipoprotein lipase (LPL), a key enzyme for the lipolytic processing of triglyceride-rich lipoproteins in capillaries¹.

“We anticipate that the acquisition of mass photometry in our laboratory is going to be a game changer in our studies on purified proteins involved in intravascular lipolysis,” said Group Leader Dr Michael Ploug. “We’ve already shown by mass photometry that the LPL inhibitor ANGPTL3/8 is not an oligomeric complex composed of three ANGPTL3 protomers and one ANGPTL8 protomer as was reported previously, but is actually a trimeric complex composed of only two ANGPTL3 protomers and one ANGPTL8 protomer. This information is self-evidently important for future studies on the regulation of LPL activity in capillaries.”

Mass photometry now provides a valuable orthogonal tool to those already available to the group for its functional and structural protein studies, proving ideal for studying proteins in low concentrations where SEC-MALS is challenged. Ploug noted, “Since our proteins generally operate in the lower nanomolar range, we need to determine their oligomeric states at these low concentrations and we found that our studies using SEC-MALS often lead to misleading conclusions as it requires higher protein concentrations. We also chose the MassFluidix HC as an add-on to the TwoMP, as some of our biophysical analyses do need to be conducted at higher concentrations.

“Compared to SEC-MALS, mass photometry is fast and provides robust and reliable data. We’re also very much impressed by the software used to control the mass photometer and evaluate the data — it’s very intuitive and easy to operate.”

With over 1000 scientific citations highlighting the bioanalytical workflow capabilities of its mass photometry and macro mass photometry systems, Refeyn’s technology is proving invaluable for a wide variety of scientific discovery, drug development and manufacturing applications. In addition to protein analysis, other published application examples include characterisation of bispecific antibody by-products (including aggregates)², lipid nanoparticles (LNPs)³, direct measurement of mRNA length⁴, and also quantification of empty, partially filled and full adeno-associated virus (AAV) vector capsids⁵.

<sub>1. Kumari, Larsen, Bondesen et al (2025). ANGPTL3/8 is an atypical unfoldase that regulates intravascular lipolysis by catalyzing unfolding of lipoprotein lipase. Proc Natl Acad Sci USA (2025) 122 (12).
2. Cramer, Franc, Heidenreich et al (2022). Characterization of high-molecular weight by-products in the production of a trivalent bispecific 2+1 heterodimeric antibody. mAbs (2022) 15 (1).
3. Wu, Zhang, Wu et al (2025). Characterization of Lipid Nanoparticles Using Macro Mass Photometry: Insights into Size and Mass. Analytica Chimica Acta (2025) 1351, 343944.
4. Schmudlach, Spear, Hua et al (2025). Mass photometry as a fast, facile characterization tool for direct measurement of mRNA length. Biol Methods Protoc (2025) 10 (1).
5. Wagner, Fuchsberger, Innthaler et al (2023). Quantification of Empty, Partially Filled and Full Adeno-Associated Virus Vectors Using Mass Photometry. Int J Mol Sci (2023) 24 (13).</sub>

Image caption: Dr Anni Kumari with Refeyn’s TwoMP mass photometer and MassFluidix HC system, newly installed at the University of Copenhagen.