Brillouin microscopy, long recognized for its ability to identify the biomechanical properties of a sample, has been hindered by slow image acquisition. This is the result of weak signal strength from Brillouin light scattering — when light interacts with a substance and thermal fluctuations or vibrations of molecules cause light to scatter. But recent advancements at the European Molecular Biology Laboratory (EMBL) appear to have overcome this limitation, using a microscope equipped with a Fourier transform spectrometer, which helped acquire 40,000 spectra/s along a 2D plane. Researchers and clinicians know that Brillouin microscopy has immense potential in biomedicine due to its ability to noninvasively measure viscosity and elasticity within a tissue sample — hallmark indications of health and disease. Vital diagnostic clues can be gleaned from the viscosity of cells and tissue, providing structural and functional information that could warn clinicians of diseases from cancer to atherosclerosis. And while Brillouin microscopy has historically taken several minutes to generate simple 2D images, which is evidently not swift enough for a clinical workflow, innovations may be clearing that hurdle. Robert Prevedel, group leader in the cell biology and biophysics unit at the EMBL in Heidelberg, Germany, helped oversee recent research, in which experiments were conducted with an optical phantom (a mixture of oil and agar beads) to test their measurements, which could be easily verified from literature. They also used their technique to examine zebrafish larvae, which are often used for their relative transparency and their ability to be penetrated by light. Prevedel said that the group now plans to build on this proof of principle and develop a more practical microscope, which will require a redesign of the main stage and optics of their instrument. Brillouin microscopy is rooted in the discovery of Brillouin light scattering, which was perceived by the French physicist Léon Brillouin more than a century ago. The modality is also at the heart of this edition’s cover story by Torsten Jähnke here. Jähnke outlines important lessons learned in the use of Brillouin for materials analysis, and how this knowledge has become applicable in the biomedical realm, providing insights into the dynamics of living cells. Using Brillouin spectra from different points in a sample, a 3D image map can be created. This information can trace the way mechanical stimuli are converted into biochemical signaling, opening a new view of processes that directly affect health. As Jähnke wrote, this has proved to be particularly valuable in cancer research, where tumor aggressiveness, marked by cell deformability, could indicate metastasis of the cancer. And these signs could evolve into precision diagnostics and therapy. Enjoy the issue! Douglas J. Farmer