Viruses threaten humans, livestock, and plants, and are difficult to combat. Imaging of viruses by light microscopy is key to uncover the nature of known and emerging viruses in the quest for finding new ways to treat viral disease and deepening the understanding of virus–host interactions. Here, we provide an overview of recent technology for imaging cells and viruses by light microscopy, in particular fluorescence microscopy in static and live-cell modes. The review lays out guidelines for how novel fluorescent chemical probes and proteins can be used in light microscopy to illuminate cells, and how they can be used to study virus infections. We discuss advantages and opportunities of confocal and multi-photon microscopy, selective plane illumination microscopy, and super-resolution microscopy. We emphasize the prevalent concepts in image processing and data analyses, and provide an outlook into label-free digital holographic microscopy for virus research.
Keywords: DNA virus; RNA virus; adeno-associated virus AAV; adenovirus; baculovirus; cell biology; computing; cytoskeleton; data analysis; endocytosis; enveloped virus; fluorescence microscopy; fluorescent virions; gene expression; gene therapy; hepatitis B virus; herpes simplex virus; herpesvirus; high-throughput screening, modeling; human immunodeficiency virus HIV; image analysis; immunofluorescence microscopy; infection; influenza virus; innate immunity; internalization; intracellular transport; light microscopy; live imaging; machine learning; membrane traffic; microscopy; nonenveloped virus; parvovirus; quantitative microscopy; receptor; simian virus 40; simulation; super-resolution; trafficking; virion uncoating; virus entry; virus infection; virus labeling.