Sub-wavelength optical fluorescence microscopy for biological applications

Abstract

Visualization of sub-cellular structures and their temporal evolution contributes substantially to our understanding of biological processes. Far-field optical microscopy is arguably the most powerful imaging technique for cells and tissues because it allows live specimens to be studied over extended periods of time with only minimal perturbation due to the measurement. In fluorescence microscopy, biomolecules or supramolecular structures of interest are specifically labeled by light-emitting moieties and thus can be imaged with excellent contrast. A disadvantage of standard optical microscopy is its moderate spatial resolution, which is restricted to about half the wavelength of visible light (∼200 nm) by fundamental physical laws governing wave optics. Consequently, molecular interactions occurring on spatial scales of 1-100 nm cannot be resolved. However, a variety of super-resolution fluorescence microscopy techniques have recently been developed that overcome the resolution limitation. Here we present a brief overview of these techniques and their application to cellular biophysics. © 2013 Springer Science+Business Media Dordrecht.