Mass photometry is a revolutionary new method of analyzing molecules. It enables the accurate mass measurements of single molecules in solution, in their native state and without the need for labels. For molecular mass measurements with unmatched sensitivity, speed and simplicity of use, a TwoMP mass photometer offers wide mass range and single-molecule resolution.
With its high sensitivity, the TwoMP is ideally suited for measurements at physiological (i.e. low) concentrations. The high dynamic range intrinsic to single molecule counting techniques ensures low-abundance species are still captured accurately.
Refeyn’s software automatically controls the acquisition process and performs the mass analysis in minutes. You can intuitively interpret the mass distribution results without the need for any prior knowledge.
A compact, bench-top instrument with minimal installation requirements. Measurements only require a few microliters of sample and clean sample-carrier slides.
Antigen-antibody interactions are a prime example of molecular systems that can be studied using mass photometry, which can be applied to determine binding affinities for mono- and multivalent interactions.
Figure 1 illustrates how mass photometry can be used to quantify molecular interactions. By measuring the mass of the antibody trastuzumab and its target antigen, Her2, individually and in mixtures, the interactions between individual antibody molecules and target antigens could be quantified.
Mass photometry can be used to characterise DNA-protein complexes, which are crucial in gene expression, replication and DNA repair.
In this example, mass photometry not only allows detection of DNA binding but also provides information on how the oligomeric state of the protein changes upon DNA binding (Figure 2).
Many proteins adopt a particular oligomeric form under certain conditions. In Figure 1, mass photometry characterises four different proteins: protein A, beta-amylase, urease and thyroglobulin. Through this characterisation, these proteins showcase a range of behaviours – from purely monomeric (as in Protein A) to a dynamic equilibrium between multiple states.
Ribosomes are macromolecular assemblies of protein and RNA, and are central sites for protein synthesis. Bacterial ribosomes (in this example from E. coli) are >2 MDa in size. Magnesium ions play a subtle yet important role in the assembly of intact (70S) complexes. In the absence of magnesium, E. coli ribosomes rapidly disassemble into their 30S and 50S subunits. Mass photometry allows us to monitor these processes (Figure).
