Posts with the tag: structured illumination
Super-resolution microscopy has received a lot of interest in the past few years, culminating in the 2014 Nobel Prize in Chemistry for the development of the STED and STORM/PALM family of techniques. Around the same time, an interesting (and mischievously titled) commentary appeared in Nature Photonics, claiming to resolve (ho ho) a misconception about a third approach to super-resolution – SIM or ‘structured illumination microscopy’. This is a technique which can be used to improve the resolution by a factor of two. The paper argues that structured illumination microscopy only provides true resolution enhancement for fluorescence imaging and none at all for scattering imaging. This is despite recent papers making claims – and apparently providing experimental evidence – to the contrary.
There’s a stark contrast between the elegant simplicity of a conventional widefield microscope and the much more complex apparatus need for point-by-point scanning in confocal microscopy. It’s this point-by-point scanning, together with a pinhole, which gives the confocal microscope its optical sectioning ability. By removing the out of focus blur which would degrade a conventional microscope image, confocal microscopes obtain crisp, clean images of thick samples, or even of in vivo tissue. The additional complexity involved with confocal operation, which includes the requirement to use a laser rather than a thermal light source, is accepted as the price that has to be paid if we want to obtain these kinds of images. But now, HiLo microscopy is offering an alternative approach which could have a number of niche applications, particularly where space or cost preclude the use of a full confocal microscopy setup.