Abstract
Microscopy has been essential to elucidate micro- and nano-scale processes in space and time, and has provided insight into cell and organismic function. It is widely employed in cell biology, microbiology, physiology, clinical sciences and virology. While label-dependent microscopy, such as fluorescence microscopy, provides molecular specificity, it has remained difficult to multiplex in live samples. In contrast, label-free microscopy reports on overall features of the specimen at minimal perturbation. Here, we discuss modalities of label-free imaging at the molecular, cellular and tissue levels, including transmitted light microscopy, quantitative phase imaging, cryogenic electron microscopy or tomography, and atomic force microscopy. We highlight how label-free microscopy is used to probe the structural organization and mechanical properties of viruses, including virus particles and infected cells across a wide range of spatial scales. We discuss the working principles of imaging procedures and analyses, and showcase how they open new avenues in virology. Finally, we discuss orthogonal approaches that enhance and complement label-free microscopy techniques.
Mini Abstract: Label-free imaging gives unprecedented insight into viruses at macroscopic, molecular and atomic levels. We present the major label-free imaging techniques and discuss how they are used for virus particles and infected cells. The power of label-free microscopy promises to enhance discovery of unknown aspects of infectious and therapeutic agents.
Petkidis, Anthony