Archive for February 2017

How to Analyze Prepared and Unprepared Geological Samples with One Digital Microscope

Full credit to the source of this post http://www.leica-microsystems.com/science-lab/how-to-analyze-prepared-and-unprepared-geological-samples-with-one-digital-microscope/

Polarized light microscopes have been used in classical earth science studies for the last 100 years. Since then a lot of progress has been made to increase the user friendliness, ergonomy, and optical performance of such microscopes. Still, one thing has not changed: Classical polarized light (compound) microscopes can only be used for prepared samples, because the working distance they offer is insufficient for whole samples. This article explains how earth scientists can analyze prepared and unprepared samples for polarized light applications with one single instrument, namely the Leica DVM6 M digital microscope. With the right choice of accessories it serves as a semi-quantitative polarization microscope.

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Mirror-Enhanced Super-Resolution Microscopy

Full credit to the source of this post http://www.leica-microsystems.com/science-lab/mirror-enhanced-super-resolution-microscopy/

Axial excitation confinement beyond the diffraction limit is crucial to the development of next-generation, super-resolution microscopy. STimulated Emission Depletion (STED) nanoscopy offers lateral super-resolution using a donut-beam depletion, but its axial resolution is still over 500 nm. Total internal reflection fluorescence microscopy is widely used for single-molecule localization, but its ability to detect molecules is limited to within the evanescent field of ~100 nm from the cell attachment surface. We find here that the axial thickness of the point spread function (PSF) during confocal excitation can be easily improved to 110 nm by replacing the microscopy slide with a mirror. The interference of the local electromagnetic field confined the confocal PSF to a 110-nm spot axially, which enables axial super-resolution with all laser-scanning microscopes.

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Epoxy Resin Embedding of Animal and Human Tissues for Pathological Diagnosis and Research

Full credit to the source of this post http://www.leica-microsystems.com/science-lab/epoxy-resin-embedding-of-animal-and-human-tissues-for-pathological-diagnosis-and-research/

Application Note for Leica EM AMW – The tissues were fixed in the modified Karnovsky fixative generally by immersion overnight (at minimum 4h at room temperature). Then pieces of approx. 1mm3 were cut with a sharp razor blade and processed for embedding in the Leica EM AMW Microwave Tissue Processor.

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Image Gallery: Application Options with Leica DM2500 LED Microscope

Full credit to the source of this post http://www.leica-microsystems.com/science-lab/galleries/image-gallery-application-options-with-leica-dm2500-led-microscope/

The number of applications in microscopy can be as manifold as life itself. Different specimens demand different contrast methods to get a decent result. Unstained cells normally do not show a very high contrast. Researchers approach this problem by either staining the specimen with dyes respectively fluorescent molecules; or adding contrast by manipulating the light passing through.

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Cultured Rat Hippocampal Neurons

Full credit to the source of this post http://www.leica-microsystems.com/science-lab/cultured-rat-hippocampal-neurons/

Application Note for Leica EM ICE – Rat Hippocampal neurons, cultured on 50 μm thick Aclar (Aclar embedding film, EMS) for 19 days, were frozen in the 100 μm deep side of lecithin coated (detailed protocol Appendix I) type A 3 mm Cu/Au carriers (Leica) and sandwiched with the flat side of lecithin coated type B 3 mm Cu/Au carriers (Leica). No additional filler was used, only cell culture medium with the addition of Hepes buffer pH 7.2 to a final concentration of 25 mM. Samples were frozen in a high-pressure freezer (Leica EM ICE).

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