Virus morphology: Insights from super-resolution fluorescence microscopy

Abstract

As epitomised by the COVID-19 pandemic, diseases caused by viruses are one of the greatest health and economic burdens to human society. Viruses are ‘nanostructures’, and their small size (typically less than 200 nm in diameter) can make it challenging to obtain images of their morphology and structure. Recent advances in fluorescence microscopy have given rise to super-resolution techniques, which have enabled the structure of viruses to be visualised directly at a resolution in the order of 20 nm. This mini-review discusses how recent state-of-the-art super-resolution imaging technologies are providing new nanoscale insights into virus structure.

Fluorescence Microscopy in Adeno-Associated Virus Research

“…Fluorescence widefield and confocal microscopy techniques are now the established standards as described above for AAV. Other virus research fields provide a multitude of examples where microscopy contributes to the understanding of molecular mechanisms such as virus entry, genome integration, expression, assembly, and immunological consequences (reviewed in [ 129 , 130 ]). For example, TIRF microscopy was used in a combination with FRET and FRAP in temporal studies determining the interplay of host proteins with the assembly of HIV at the plasma membrane [ 131 ].…”

Rapid and timely virus detection by optical technologies: prospects for future viruses’ prevalence

“…In addition, nowadays, there exist several methodologies developed for super-resolution fluorescence microscopy (SRFM) including structured-illumination microscopy (SIM), stimulated emission depletion microscopy (STED), photoactivated localization microscopy (PALM), fluorescence photoactivation localization microscopy (FPALM), and stochastic optical reconstruction microscopy (STORM). Each of these techniques has capabilities and weaknesses in biological research individually [49]. For many years, some imaging techniques such as confocal microscopy and multiphoton fluorescence microscopy have bypassed the diffraction barrier in optical systems, which allows optical sectioning and thus, 3D-imaging [49].…”

“…Each of these techniques has capabilities and weaknesses in biological research individually [49]. For many years, some imaging techniques such as confocal microscopy and multiphoton fluorescence microscopy have bypassed the diffraction barrier in optical systems, which allows optical sectioning and thus, 3D-imaging [49]. 4Pi microscopy and I5M apply two opposing microscope objective lenses to enhance the NA of the microscope and thereby improve lateral resolution by a modest amount, but the axial resolution to ˜100nm [50,51].…”

Addressing the Silent Spread of Monkeypox Disease with Advanced Analytical Tools

“…However, the major limitation of fluorescence optical microscopy is its physical limitations in optics, mainly diffraction limit. [161] The diffraction limitation makes it more difficult to study and image the nanoscale macromolecules such as viruses. [162] Recently, several technological developments have been performed to enhance the functionality, resolution, and sensitivity of light microscopes, [163] especially the invention of super-resolution microscopy (SRM).…”