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Photonics 2017, 4(2), 33;

XL-SIM: Extending Superresolution into Deeper Layers

Bio Imaging Zentrum der Ludwig-Maximilians-Universität München, 82152 Martinsried, Germany;
TILL I.D. GmbH, 82152 Planegg/Martinsried, Germany
Authors to whom correspondence should be addressed.
Received: 14 March 2017 / Revised: 7 April 2017 / Accepted: 13 April 2017 / Published: 20 April 2017
(This article belongs to the Special Issue Superresolution Optical Microscopy)
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Of all 3D-super resolution techniques, structured illumination microscopy (SIM) provides the best compromise with respect to resolution, signal-to-noise ratio (S/N), speed and cell viability. Its ability to achieve double resolution in all three dimensions enables resolving 3D-volumes almost 10× smaller than with a normal light microscope. Its major drawback is noise contained in the out-of-focus-signal, which—unlike the out-of-focus signal itself—cannot be removed mathematically. The resulting “noise-pollution” grows bigger the more light is removed, thus rendering thicker biological samples unsuitable for SIM. By using a slit confocal pattern, we employ optical means to suppress out-of-focus light before its noise can spoil SIM mathematics. This not only increases tissue penetration considerably, but also provides a better S/N performance and an improved confocality. The SIM pattern we employ is no line grid, but a two-dimensional hexagonal structure, which makes pattern rotation between image acquisitions obsolete and thus simplifies image acquisition and yields more robust fit parameters for SIM. View Full-Text
Keywords: structured illumination; confocal microscopy; line-confocal microscopy; 3D-super resolution; hexagonal SIM structured illumination; confocal microscopy; line-confocal microscopy; 3D-super resolution; hexagonal SIM

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Schropp, M.; Seebacher, C.; Uhl, R. XL-SIM: Extending Superresolution into Deeper Layers. Photonics 2017, 4, 33.

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