Leica Science Lab - Tag : Fluorescence https://www.leica-microsystems.com//science-lab/tag/fluorescence/ Article tagged with Fluorescence en-US https://www.leica-microsystems.com/72986 Widefield Microscopy TIRF Microscopy Studying Actin Cytoskeleton and Microfilament Assembly This article demonstrates how actin microfilament assemblies can be clearly visualized with super-resolution at the plasma membrane of a cell using a DMi8 S Infinity TIRF High Power imaging solution. To better understand how pathogens disrupt host cell signaling and cytoskeletal membrane trafficking during invasion and intracellular replication, infection of the S. frugiperda Sf21 moth larva by the baculovirus A. californica Multiple Nucleopolyhedrovirus (AcMNPV) was used as a model. The goal of the study was not only to gain insights into the interaction between the AcMNPV virus and actin, but also normal cytoskeleton functions. https://www.leica-microsystems.com/science-lab/studying-actin-cytoskeleton-and-microfilament-assembly/ Thu, 24 Jun 2021 09:53:00 +0000 https://www.leica-microsystems.com/72745 Widefield Microscopy Fluorescence Microscopy Fission Yeast Actomyosin Ring Integrity This article demonstrates that the stress-activated protein kinase pathway (SAPK) and its effector, MAPK Sty1, downregulates CAR assembly in the fission yeast Schizosaccharomyces pombe when its integrity becomes compromised during cytoskeletal damage and stress by the reduction of formin For3 levels. Cytokinesis, which enables the physical separation of daughter cells once mitosis has been completed, is executed in fungal and animal cells by a contractile actin- and myosin-based ring (CAR). https://www.leica-microsystems.com/science-lab/fission-yeast-actomyosin-ring-integrity/ Fri, 28 May 2021 07:56:00 +0000 PhD James DeRose https://www.leica-microsystems.com/72465 Confocal Microscopy Quantitative Imaging Label-free Differentiation of Microplastics Phasor analysis for fluorescence lifetime imaging microscopy (FLIM) is a powerful and fitting-free tool that provides a 2D graphical assessment of pixel-accurate lifetime distributions in a sample image. In biology and biomedical research, this tool is used in a variety of applications, such as protein-protein interactions, signaling events in cells, or to distinguish spectrally overlapping fluorophores. In this study, we show that phasor analysis is also suitable for the identification and differentiation of anthropogenic materials, such as autofluorescent microplastics. https://www.leica-microsystems.com/science-lab/label-free-differentiation-of-microplastics/ Wed, 12 May 2021 13:20:00 +0000 PhD Adrian Monteleone https://www.leica-microsystems.com/72481 THUNDER Imaging Widefield Microscopy Fluorescence Microscopy Cytosolic Calcium Ions in Melanoma Cancer Cells In this article, a ratiometric fluorometric method for cytosolic calcium ion (Ca2+) measurement in cultured melanoma cells using Fura 2-AM cell loading and fluorescence microscopy imaging is presented in detail. Cytosolic Ca2+ levels are maintained at low nanomolar concentrations and disruption of Ca2+ homeostasis is associated with cell/tissue damage. https://www.leica-microsystems.com/science-lab/cytosolic-calcium-ion-measurements/ Wed, 12 May 2021 07:56:00 +0000 PhD James DeRose https://www.leica-microsystems.com/48565 Neurosurgery Surgical Microscopy How Augmented Reality is Transforming Vascular Neurosurgery Augmented Reality is changing surgery, with new information helping to improve the precision and safety of procedures. This is especially true in vascular neurosurgery where Augmented Reality is redefining visualization standards. Prof. Raphael Guzman is a Professor of Neurosurgery at the University of Basel in Switzerland and Vice-chair of the Department of Neurosurgery. He uses GLOW800 Augmented Reality fluorescence, a new approach to vascular fluorescence imaging. He believes it is an advantage for his surgical practice, especially for aneurysm surgery. https://www.leica-microsystems.com/science-lab/how-augmented-reality-is-transforming-vascular-neurosurgery/ Mon, 15 Mar 2021 11:51:00 +0000 Corporate Communications, Professor Guzman Raphael https://www.leica-microsystems.com/48987 THUNDER Imaging Fluorescence Microscopy Widefield Microscopy Studying Cell Division Cell division is a biological process during which all cellular components must be distributed among the daughter cells. The division process requires firm coordination for success. Microscopy is utilized to observe this procedure in living cells. https://www.leica-microsystems.com/science-lab/studying-cell-division/ Tue, 09 Mar 2021 13:25:00 +0000 Ph.D. Javier Encinar del Dedo, Ph.D. Elena Rebollo, Dr. Christoph Greb, PhD James DeRose https://www.leica-microsystems.com/48615 THUNDER Imaging Fluorescence Microscopy Widefield Microscopy Improvement of Imaging Techniques to Understand Organelle Membrane Cell Dynamics Understanding cell functions in normal and tumorous tissue is a key factor in advancing research of potential treatment strategies and understanding why some treatments might fail. Single-cell analysis is crucial in biomedical research to unravel which cellular and molecular pathways are altered in complex diseases such as cancer. https://www.leica-microsystems.com/improvement-of-imaging-techniques-to-understand-organelle-membrane-cell-dynamics/ Mon, 15 Feb 2021 12:11:00 +0000 Corporate Communications https://www.leica-microsystems.com/48441 Surgical Microscopy Neurosurgery Microscopy Enhanced Navigation in Neurosurgery Neurosurgical procedures are very complex and delicate, especially when they involve craniotomy. Surgeons need to be extremely focused and concentrated throughout. Navigation plays an essential role, helping to precisely execute surgical plans. https://www.leica-microsystems.com/microscopy-enhanced-navigation-in-neurosurgery/ Thu, 04 Feb 2021 09:52:00 +0000 Professor Phillippe Bijlenga, Corporate Communications https://www.leica-microsystems.com/45747 THUNDER Imaging Fluorescence Microscopy Live-Cell Imaging Widefield Microscopy Studying Autoimmune Disease This article discusses how autoimmune diseases, like systemic lupus erythematosus (SLE), can be studied more efficiently using thick, 3D kidney tissue specimens visualized with a THUNDER Imager . SLE can lead to lupus nephritis (LN) when blood vessels in the kidney become inflamed. If left untreated, eventually kidney failure could be the result. A better understanding of the initiation of LN is important for the developing treatments. This goal necessitates the study of 3D kidney specimens. https://www.leica-microsystems.com/studying-autoimmune-disease/ Wed, 27 Jan 2021 09:37:00 +0000 PhD Vikram Kohli, PhD Ameet Chimote, PhD James DeRose https://www.leica-microsystems.com/45279 Confocal Microscopy Quantitative Imaging How FLIM Microscopy helps to detect microplastic pollution The use of autofluorescence in biological samples is a widely used method to gain detailed knowledge about systems or organisms. This property is not only found in biological systems, but also anthropogenic materials, such as plastics, can emit autofluorescence. Measuring the temporal resolution of this emitted autofluorescence with fluorescence lifetime imaging microscopy (FLIM) generates data on fluorescence decay, i.e. the fluorescence lifetime (τ). Our study showed that the fluorescence lifetime can be used for a label-free characterization of plastics (microplastics). https://www.leica-microsystems.com/science-lab/how-flim-microscopy-helps-to-detect-microplastic-pollution/ Mon, 28 Dec 2020 09:50:00 +0000 PhD Adrian Monteleone https://www.leica-microsystems.com/44607 Surgical Microscopy Plastic Reconstructive Fluorescence Microscopy Immediate Breast Reconstruction: Benefits of GLOW800 Augmented Reality Dr. Harold Chatel is a Plastic and Reconstructive Surgeon in a leading hospital in Paris, France. One of his areas of expertise is oncological reconstructive surgery and immediate breast reconstruction. The hospital he works for is one of the World’s Best Oncology Hospitals according to the Newsweek 2021 ranking, which recognizes hospitals with state-of-the-art facilities and accomplished physicians. https://www.leica-microsystems.com/immediate-breast-reconstruction-benefits-of-glow800-augmented-reality/ Mon, 23 Nov 2020 16:56:00 +0000 Dr. Harold Chatel https://www.leica-microsystems.com/44601 Surgical Microscopy Plastic Reconstructive Fluorescence Microscopy Oncological Reconstructive Surgery with the Leica M530 OHX Microscope Precision is essential in oncological reconstructive surgery, in particular when it relies on free flap techniques. Microsurgical microscopes provide optimal visualization and help streamline the surgical workflow, without interruptions, to ensure successful reconstruction and avoid complications. https://www.leica-microsystems.com/oncological-reconstructive-surgery-with-the-leica-m530-ohx-microscope/ Mon, 23 Nov 2020 16:24:00 +0000 Dr. Harold Chatel https://www.leica-microsystems.com/44595 Surgical Microscopy Plastic Reconstructive Fluorescence Microscopy Oncological Reconstructive Surgery: Why Use a Microscope Recent advances in microsurgery are enhancing breast reconstruction for oncology patients, allowing both functional and aesthetic rehabilitation. More and more surgeons are adopting surgical microscopes with a built-in fluorescence camera as an alternative to microsurgical glasses and a standalone camera. https://www.leica-microsystems.com/oncological-reconstructive-surgery-why-use-a-microscope/ Mon, 23 Nov 2020 16:15:00 +0000 Dr. Harold Chatel, Dr. Anne-Sophie Reguesse https://www.leica-microsystems.com/44590 Surgical Microscopy Plastic Reconstructive Fluorescence Microscopy Oncological Reconstructive Surgery: Benefits of Microscope & Integrated Vascular Fluorescence Use Oncological reconstructive surgery requires high precision and attention to details. It can pose a number of challenges: long operating time, flap necrosis and other complications. Leica visualization solutions provide enhanced ergonomics and high-quality optical features to overcome these challenges. https://www.leica-microsystems.com/oncological-reconstructive-surgery-benefits-of-microscope-integrated-vascular-fluorescence-use/ Mon, 23 Nov 2020 12:36:00 +0000 Dr. Harold Chatel https://www.leica-microsystems.com/44422 Confocal Microscopy Live-Cell Imaging Advanced Quantitative Fluorescence Microscopy to Probe the Molecular Dynamics of Viral Entry Viral entry into the host cell requires the coordination of many cellular and viral proteins in a precise order. Modern microscopy techniques are now allowing researchers to investigate these interactions with higher spatiotemporal resolution than ever before. Here we present two examples from the field of HIV research that make use of an innovative quantitative imaging approach as well as cutting edge fluorescence lifetime-based confocal microscopy methods to gain novel insights into how HIV fuses to cell membranes and enters the cell. https://www.leica-microsystems.com/advanced-quantitative-fluorescence-microscopy-to-probe-the-molecular-dynamics-of-viral-entry/ Wed, 11 Nov 2020 09:48:00 +0000 PhD Ben Libberton https://www.leica-microsystems.com/44417 Surgical Microscopy Neuroscience Neurosurgery Neurosurgery with Heads-up Display In the following video interviews Prof. Dr. Raphael Guzman, Vice Chairman of the Department of Neurosurgery at the University Hospital in Basel, Switzerland, talks about his experience in heads-up surgery with the ARveo augmented reality microscope in surgery. https://www.leica-microsystems.com/science-lab/neurosurgery-with-heads-up-display/ Wed, 11 Nov 2020 08:10:00 +0000 Mariya Yaneva, MD Robert Ibe https://www.leica-microsystems.com/28027 Surgical Microscopy Augmented Reality (AR) Fluorescence Image Gallery Building on a decade of leadership in fluorescence imaging technology, GLOW800 AR fluorescence is the first of many modalities based on the proprietary GLOW AR platform. The sophisticated imaging sensors and algorithms of GLOW AR acquire, optimize, and combine multiple spectral bands of light. The result is natural coloring of tissue anatomy and accurate representation of fluorescence intensity. https://www.leica-microsystems.com/science-lab/galleries/augmented-reality-ar-fluorescence-image-gallery/ Mon, 31 Aug 2020 10:28:00 +0000 MD Robert Ibe https://www.leica-microsystems.com/30687 THUNDER Imaging Fluorescence Microscopy Stereo Microscopy Studying Adipose Tissue Development and Expansion This article discusses sharp, high-contrast imaging of whole mount adipose (fat) tissues specimens, which are thick and round (unsectioned), with a THUNDER Imager using Computational Clearing. Adipose tissue is important for the regulation of metabolism. The rise in obesity and health matters related to it, like diabetes and heart disease, has led to more research on adipose tissue development and expansion. Fluorescence microscopy is often used to investigate adipose tissue. However, when imaging 3D, whole mount specimens, specific challenges, like reducing image background and focusing over large, highly curved surfaces, should be overcome. https://www.leica-microsystems.com/science-lab/studying-adipose-tissue-development-and-expansion/ Thu, 27 Aug 2020 08:00:00 +0000 PhD James DeRose, PhD Qing Tang https://www.leica-microsystems.com/30694 Confocal Microscopy Fluorescence Microscopy Infection of the novel coronavirus SARS-CoV-2 can be blocked by a human monoclonal antibody Vaccines and targeted therapeutics for treatment of the respiratory disease COVID-19, caused by the coronavirus SARS-CoV-2, are currently lacking. Based on the results of this study, it was reported for the first time that a human monoclonal antibody, 47D11, can neutralize SARS-CoV-2 in cell culture. This cross-neutralizing antibody targets a communal epitope on the virus via a mechanism that is independent of receptor-binding inhibition. It will be useful for development of antigen detection tests and serological assays targeting SARS-CoV-2. https://www.leica-microsystems.com/science-lab/infection-of-the-novel-coronavirus-sars-cov-2-can-be-blocked-by-a-human-monoclonal-antibody/ Mon, 24 Aug 2020 12:29:00 +0000 https://www.leica-microsystems.com/30577 Surgical Microscopy Neurosurgery Augmented Reality and Fluorescence: Clinical Uses in Cerebrovascular and Skull Base Neurosurgery In this webinar Dr. Bendok and Dr. Morcos explain how Augmented Reality and Fluorescence can enhance visualization and support surgical decision making. They present first-hand experience of the GLOW AR platform from Leica Microsystems. See examples of the use of GLOW800 AR fluorescence in cerebrovascular surgery such as aneurysms, bypasses, AVMs and skull base pathology. https://www.leica-microsystems.com/science-lab/augmented-reality-and-fluorescence-clinical-uses-in-cerebrovascular-and-skull-base-neurosurgery/ Thu, 20 Aug 2020 10:39:00 +0000 https://www.leica-microsystems.com/28031 Basics in Microscopy Fluorescence Microscopy Widefield Microscopy Getting Sharper 3D Images of Thick Biological Specimens with Widefield Microscopy Widefield fluorescence microscopy is often used to visualize structures in life science specimens and obtain useful information. With the use of fluorescent proteins or dyes, discrete specimen components are marked in a highly specific manner. To fully understand a structure, visualizing it in 3 dimensions can be necessary, but certain challenges are faced when doing so with microscopy. https://www.leica-microsystems.com/science-lab/getting-sharper-3d-images-of-thick-biological-specimens-with-widefield-microscopy/ Tue, 18 Aug 2020 08:00:00 +0000 Dr. Christoph Greb, PhD James DeRose, Dr. Rolf T. Borlinghaus https://www.leica-microsystems.com/28307 Confocal Microscopy Learn how to Remove Autofluorescence from your Confocal Images Autofluorescence can significantly reduce what you can see in a confocal experiment. This article explores causes of autofluorescence as well as different ways to remove it, from simple media fixes to powerful technological solutions. Removing this background is essential to correctly interpreting small differences in the signals present within your sample. Find out how in this article. https://www.leica-microsystems.com/science-lab/learn-how-to-remove-autofluorescence-from-your-confocal-images/ Mon, 23 Mar 2020 09:58:00 +0000 PhD Ben Libberton https://www.leica-microsystems.com/26903 Confocal Microscopy Pore Scale Visualization of Drainage in 3D Porous Media by Confocal Microscopy This work reports new interesting findings concerning porous media infiltration which have direct implications for the fields of energy (oil recovery) and environment (CO2 sequestration and aquifer remediation). https://www.leica-microsystems.com/science-lab/pore-scale-visualization-of-drainage-in-3d-porous-media-by-confocal-microscopy/ Mon, 28 Oct 2019 07:07:00 +0000 D.Sc. Débora F. do Nascimento, M.Sc. Ronaldo Vimieiro Junior, PhD David R. Barbero, PhD Marcio Carvalho https://www.leica-microsystems.com/6282 TIRF Microscopy TIRF Publication List This monthly updated references list presents current papers using Leica AM TIRF in the major application fields for TIRF microscopy. https://www.leica-microsystems.com/science-lab/tirf-publication-list/ Tue, 03 Sep 2019 12:50:00 +0000 https://www.leica-microsystems.com/26267 Fluorescence Microscopy Stereo Microscopy Improved tree-ring visualization using autofluorescence Autofluorescence can be a very practical tool for the visualization of growth rings in wood, especially when these structures are hard to distinguish, like in tropical trees. Tree rings are largely used for the investigation of growth rate, forest dynamics and management, paleoclimate and climate change, among other applications. https://www.leica-microsystems.com/science-lab/improved-tree-ring-visualization-using-autofluorescence/ Tue, 23 Jul 2019 16:00:00 +0000 Ph.D. Piero Bagnaresi, PhD James DeRose https://www.leica-microsystems.com/24696 Confocal Microscopy What is a Spectral Detector (SP Detector)? The SP detector from Leica Microsystems denotes a compound detection unit for point scanning microscopes, in particular confocal microscopes. The SP detector splits light into up to 5 spectral bands. The bands are independent and continuously tunable within the full visible spectrum. The light in each band is detected by a light sensor: a photomultiplier tube (PMT) or a Hybrid Detector (HyD). https://www.leica-microsystems.com/science-lab/what-is-a-spectral-detector-sp-detector/ Sun, 10 Mar 2019 23:00:00 +0000 https://www.leica-microsystems.com/24585 Confocal Microscopy A Molecular Link between Cell Migration and Vascular Disease Blood vessels transport vital nutrients and oxygen to all the cells in the body. Guided by a complex signaling network, endothelial cells sprout, proliferate, and migrate to form those vessels. One of the processes of vascular formation is angiogenesis, the growth of new vessels from pre-existing ones. Our current knowledge of the mechanisms controlling angiogenesis and vascular stability is still limited. However, these mechanisms play important roles in the pathophysiology of cancer, diabetes and stroke. Understanding the factors that control healthy and unhealthy blood vessel development is fundamental to prevent and fight such diseases. https://www.leica-microsystems.com/science-lab/a-molecular-link-between-cell-migration-and-vascular-disease/ Wed, 19 Dec 2018 23:00:00 +0000 Dr. Julia Roberti https://www.leica-microsystems.com/20350 Widefield Microscopy Proline Metabolism is Essential for Trypanosoma brucei brucei Survival in the Tsetse Vector Bloodsucking insects play a major role in the transmission of pathogens that cause major tropical diseases. Their capacity to transmit these diseases is directly associated with the availability and turnover of energy sources. Proline is the main readily-mobilizable fuel of the tsetse fly, which is the vector of sub-species of Trypanosoma brucei parasites that cause human sleeping sickness and are partly responsible for animal trypanosomiasis (Nagana disease) in sub-Saharan Africa. https://www.leica-microsystems.com/science-lab/proline-metabolism-is-essential-for-trypanosoma-brucei-brucei-survival-in-the-tsetse-vector/ Sun, 29 Jul 2018 22:00:00 +0000 https://www.leica-microsystems.com/20323 Confocal Microscopy Which Sensor is the Best for Confocal Imaging? The Hybrid Photodetectors (HyD) are! Why that is the case is explained in this short Science Lab article. https://www.leica-microsystems.com/science-lab/which-sensor-is-the-best-for-confocal-imaging/ Mon, 16 Jul 2018 22:00:00 +0000 Holger Birk https://www.leica-microsystems.com/20180 Confocal Microscopy Coherent Raman Scattering (CRS) Chemical Basis for Alteration of an Intraocular Lens Using a Femtosecond Laser The chemical basis for the alteration of the refractive properties of an intraocular lens with a femtosecond laser was investigated. Three different microscope setups have been used for the study: Laser Induced Fluorescence (LIF) microscopy, Raman microscopy and coherent anti-Stokes Raman Scattering (CARS) microscopy. https://www.leica-microsystems.com/science-lab/chemical-basis-for-alteration-of-an-intraocular-lens-using-a-femtosecond-laser/ Sun, 27 May 2018 22:00:00 +0000 https://www.leica-microsystems.com/19773 Fluorescence Microscopy Basics in Microscopy The Fundamentals and History of Fluorescence and Quantum Dots At some point in your research and science career, you will no doubt come across fluorescence microscopy. This ubiquitous technique has transformed the way in which microscopists can image, tag and trace anything from whole organisms to single proteins and beyond. In this article, we will examine what is meant by "fluorescence", the history and basic physics behind its definition, the discovery and application of Green Fluorescent Protein (GFP) and a look at the rapidly expanding field of fluorescent probes including Quantum Dots. https://www.leica-microsystems.com/science-lab/the-fundamentals-and-history-of-fluorescence-and-quantum-dots/ Wed, 15 Nov 2017 16:44:00 +0000 PhD Martin Wilson https://www.leica-microsystems.com/19548 Widefield Microscopy Basics in Microscopy Introduction to Widefield Microscopy One of the most basic microscopy techniques is known as ‘Widefield Microscopy’. It is fundamentally any technique in which the entire specimen of interest is exposed to the light source with the resulting image being viewed either by the observer or a camera (which can also be attached to a computer monitor). https://www.leica-microsystems.com/science-lab/introduction-to-widefield-microscopy/ Thu, 29 Jun 2017 11:31:00 +0000 PhD Martin Wilson https://www.leica-microsystems.com/19429 Fluorescence Microscopy What is Photomanipulation? The term photomanipulation describes a wide range of techniques that enable the microscopist the transition from passive observer to instigator of events by offering a way of interacting with their sample via targeted illumination. Typically researchers are trying to observe specific processes of interest in order to understand the underlying biological process. Microscopists are often forced to hunt through large populations of cells or acquire hours of time laps footage before they’re able to observe events of interest and in many cases it’s simply not possible to observe certain processes using conventional microscopy techniques alone. Photomanipulation tools enable the microscopist to initiate biological events, precisely adjusting sample labeling, biological activity, local chemical environments and in some instances physically destroy parts of their specimen. https://www.leica-microsystems.com/science-lab/what-is-photomanipulation/ Mon, 15 May 2017 07:59:00 +0000 Dr. Peter Laskey, Dr. Christoph Greb, Dr. Oliver Schlicker https://www.leica-microsystems.com/6395 Fluorescence Microscopy Photoactivatable, photoconvertible, and photoswitchable Fluorescent Proteins Fluorescent proteins (FPs) such as GFP, YFP or DsRed are powerful tools to visualize cellular components in living cells. Nevertheless, there are circumstances when classical FPs reach their limits. Watching dedicated, spatially limited protein populations of a certain protein of interest is impossible with common FPs, since they are expressed throughout the entire cell. At this point photoactivatable, photoconvertible and photoswitchable fluorescent proteins enter the stage. The members of this fluorescence toolkit can be activated from a non-fluorescent state, they can change their emission spectrum, or they are even able to be reversibly switched "on and off". With the help of these “optical highlighters”, researchers can track a distinct protein population over time by activating respectively converting their fluorescence with a spatially defined light beam of a given wavelength. https://www.leica-microsystems.com/science-lab/photoactivatable-photoconvertible-and-photoswitchable-fluorescent-proteins/ Thu, 04 May 2017 11:31:00 +0000 Dr. Christoph Greb https://www.leica-microsystems.com/19257 Stereo Microscopy Fluorescence Microscopy Work Efficiently in Developmental Biology and Medical Research with Stereo Microscopy: Rodent and Small Animal Surgery This report provides information which can help improve the routine work of scientists and technicians performing studies involving surgery on small animals and rodents, i.e. mice, rats, hamsters etc., for developmental biology or medical research. The aim is to help make the work steps efficient and cost-effective, where the employment of microscopes is necessary. It also gives useful hints and details on the various microscopes which can be used in a developmental biology or medical research laboratory where small animal or rodent surgery is exploited. https://www.leica-microsystems.com/science-lab/work-efficiently-in-developmental-biology-and-medical-research-with-stereo-microscopy-rodent-and-small-animal-surgery/ Mon, 27 Mar 2017 08:08:00 +0000 PhD James DeRose, PhD Heinrich Bürgers, MSc Ayyakkannu Ayyanan, MD Cathrin Brisken https://www.leica-microsystems.com/18935 Confocal Microscopy Fluorescence Microscopy Multispectral Phloem-Mobile Probes: Properties and Applications Using Arabidopsis (Arabidopsis thaliana) seedlings, we identified a range of small fluorescent probes that entered the translocation stream and were unloaded at the root tip. These probes had absorbance/emission maxima ranging from 367/454 to 546/576 nm and represent a versatile toolbox for studying phloem transport. Of the probes that we tested, naturally occurring fluorescent coumarin glucosides (esculin and fraxin) were phloem loaded and transported in oocytes by the sucrose transporter, AtSUC2. Arabidopsis plants in which AtSUC2 was replaced with barley (Hordeum vulgare) sucrose transporter (HvSUT1), which does not transport esculin in oocytes, failed to load esculin into the phloem. https://www.leica-microsystems.com/science-lab/multispectral-phloem-mobile-probes-properties-and-applications/ Tue, 29 Nov 2016 16:44:00 +0000 https://www.leica-microsystems.com/18806 Super-Resolution Practical Guide for Excellent GSDIM Super-Resolution Images Do you know that most protists and bacteria lack in one feature that each of our body cell has? Our cells are touch and communicate with one another. They send and receive a variety of signals that coordinate their behavior to act together as a functional multicellular organism. Exploring the way of cellular communication and the ways how the cell surface interacts to organize tissues and body structures is of great interest. Kees Jalink and his team of scientists at the Netherlands Cancer Institute (NKI) in Amsterdam obtained new scientific insights into the molecular architecture of hemidesmosomes, cytoskeletal components, cell surface receptors and vesicular proteins with the help of Ground-State-Depletion (GSD)/ dSTORM microscopy. In this interview, Kees Jalink comments on their developments in imaging chambers, buffer conditions and image analysis to get the perfect super resolution image. https://www.leica-microsystems.com/science-lab/practical-guide-for-excellent-gsdim-super-resolution-images/ Wed, 26 Oct 2016 06:58:00 +0000 PhD Kees Jalink, PhD Tamara Straube, MSc Leila Nahidiazar, MSc Daniela Leyton Puig https://www.leica-microsystems.com/17476 Stereo Microscopy Live-Cell Imaging Fluorescence Microscopy Work More Efficiently In Developmental Biology With Stereo Microscopy: Fruit Flies (Drosophila Melanogaster) For scientists and technicians working with fruit flies, most often genus Drosophila, this report is intended to give useful information to help improve daily laboratory work by making the steps of fly pushing, fluorescent screening, dissection, and documentation/imaging more efficient. It also details various possibilities for properly equipping or stocking a fly lab. https://www.leica-microsystems.com/science-lab/work-more-efficiently-in-developmental-biology-with-stereo-microscopy-fruit-flies-drosophila-melanogaster/ Thu, 22 Sep 2016 08:58:00 +0000 PhD Heinrich Bürgers, PhD James DeRose, Ph.D. Adam Cliffe https://www.leica-microsystems.com/18801 Super-Resolution Fluorescence Microscopy Measuring the 3D STED-PSF with a new Type of Fluorescent Beads A new type of fluorescent bead is presented by GATTAquant. These beads, called GATTA-Beads, are characterized by a small diameter (23 nm), high intensity and size uniformity. In combination with state-of the-art STED microscopes such as the Leica TCS SP8 STED 3X and high-end image restoration methods available in the Huygens Software, it is shown that these new beads can be used for accurate STED PSF characterization in 3D. Furthermore, it is shown that the measured 3D STED-PSF can be used to improve image restoration quality in combination with STED deconvolution methods available in the Huygens Software. https://www.leica-microsystems.com/science-lab/measuring-the-3d-sted-psf-with-a-new-type-of-fluorescent-beads/ Wed, 21 Sep 2016 06:54:00 +0000 PhD Jürgen J. Schmied, MSc Remko Dijkstra, Ph.D. Max B. Scheible, Ph.D. Giulia M. R. De Luca, PhD Jochen J. Sieber https://www.leica-microsystems.com/18691 Stereo Microscopy Confocal Microscopy Fluorescence Microscopy Work Efficiently in Developmental Biology with Stereo and Confocal Microscopy: C. elegans For scientists, technicians, and teachers working with the worm C. elegans in the research lab or classroom, this report is intended to give useful information to help improve their daly work. The aim is to make the work steps of worm picking, transgenesis, RNA interference, screening, and functional imaging efficient. It also details the various possibilities for equipping a research worm lab or biology classroom/teaching lab explaining worm methods. https://www.leica-microsystems.com/science-lab/work-efficiently-in-developmental-biology-with-stereo-and-confocal-microscopy-c-elegans/ Mon, 19 Sep 2016 06:09:00 +0000 PhD James DeRose, PhD Heinrich Bürgers, PhD Martin Gamerdinger https://www.leica-microsystems.com/13942 Fluorescence Microscopy Quantitative Imaging Video Talk by Roger Tsien: Fluorescent Protein Indicators In this talk, Roger Tsien discusses how fluorescent proteins have been turned into indicators for a wide variety of biological molecules, including pH, ions, redox potential, and signaling molecules like phosphoinositides. The talk also covers reporters used to measure the activity of enzymes like kinases, phosphatases, and proteases. It covers both single proteins whose intensity or wavelength change, as well as reporters using Förster resonance energy transfer (FRET). https://www.leica-microsystems.com/science-lab/video-talk-by-roger-tsien-fluorescent-protein-indicators/ Tue, 16 Aug 2016 10:29:00 +0000 PhD Roger Y. Tsien https://www.leica-microsystems.com/15428 Confocal Microscopy Live-Cell Imaging Highly Selective Fluorescent and Colorimetric Probe for Live-cell Monitoring of Sulphide Based on Bioorthogonal Reaction H2S is the third endogenously generated gaseous signaling compound and has also been known to involve a variety of physiological processes. To better understand its physiological and pathological functions, efficient methods for monitoring of H2S are desired. Azide fluorogenic probes are popular because they can take place bioorthogonal reactions. In this work, by employing a fluorescein derivative as the fluorophore and an azide group as the recognition unit, we reported a new probe 5-azidofluorescein for H2S with improved sensitivity and selectivety. https://www.leica-microsystems.com/science-lab/highly-selective-fluorescent-and-colorimetric-probe-for-live-cell-monitoring-of-sulphide-based-on-bioorthogonal-reaction/ Fri, 29 Jul 2016 11:41:00 +0000 https://www.leica-microsystems.com/17468 Basics in Microscopy Widefield Microscopy Introduction to Digital Camera Technology A significant majority of modern optical microscopy techniques require the use of a digital camera. By working with digital devices researchers can observe specimens on a screen in real time or acquire and store images and quantifiable data. Here we introduce the basic principles behind digital camera technologies commonly encountered in scientific imaging. https://www.leica-microsystems.com/science-lab/introduction-to-digital-camera-technology/ Tue, 02 Feb 2016 16:40:00 +0000 Dr. Christoph Greb, Dr. Peter Laskey, Dr. Karin Schwab https://www.leica-microsystems.com/13262 Quantitative Imaging FRAP with TCS SP8 Resonant Scanner Fast FRAP experiments need a sufficient number of measurement points for meaningful interpretation and fitting analysis. To study very fast translocational processes, the use of a resonant scanner (RS) is preferred. The advantage in using FRAP with the RS is that statistics are much better in experiments that require fast acquisition: If the half time of recovery is about 0.5 sec you may have only about 3 to 4 data points using the conventional scanner, whereas with the resonant scanner you can get about 20 data points. https://www.leica-microsystems.com/science-lab/frap-with-tcs-sp8-resonant-scanner/ Tue, 26 Jan 2016 15:39:00 +0000 Dr. Jan Schröder https://www.leica-microsystems.com/13935 Fluorescence Microscopy Video Talk by Roger Tsien: Fluorescent Proteins Live cell imaging has been revolutionized by the discovery of the green fluorescent protein (GFP). This lecture covers the history of GFP, how it folds and becomes fluorescent, how it has been mutated to produce additional colors (blue, cyan, yellow), and the discovery of red fluorescent proteins from corals. It also covers novel photoswitchable and photoactivatible fluorescent proteins, whose color can be changed by light, and new infrared fluorescent proteins. https://www.leica-microsystems.com/science-lab/video-talk-by-roger-tsien-fluorescent-proteins/ Wed, 07 Oct 2015 16:55:00 +0000 PhD Roger Y. Tsien https://www.leica-microsystems.com/15295 Fluorescence Microscopy How to Prepare Your Specimen for Immunofluorescence Microscopy Immunofluorescence (IF) is a powerful method for visualizing intracellular processes, conditions and structures. IF preparations can be analyzed by various microscopy techniques (e.g. CLSM, Epifluorescence, TIRF, GSDIM), depending on the application or the researcher’s interest. Meanwhile, IF has become indispensable for a large number of research groups which have at least access to a simple fluorescence microscope. https://www.leica-microsystems.com/science-lab/how-to-prepare-your-specimen-for-immunofluorescence-microscopy/ Mon, 13 Apr 2015 14:22:00 +0000 Florian Hoff https://www.leica-microsystems.com/13946 TIRF Microscopy Video Talk by Daniel Axelrod: Total Internal Reflection Fluorescence (TIRF) Microscopy Total Internal Reflection Fluorescence (TIRF) Microscopy is a technique that only illuminates dye molecules near a surface. In this video, the pioneer of TIRF Microscopy describes what this technique is used for, explains the principles of the evanescent wave, gives many examples of different microscope configurations used in TIRF, and shows how polarized light TIRF can be used to image membrane orientation. https://www.leica-microsystems.com/science-lab/video-talk-by-daniel-axelrod-total-internal-reflection-fluorescence-tirf-microscopy/ Mon, 09 Mar 2015 08:45:00 +0000 https://www.leica-microsystems.com/15077 Light Sheet Microscopy Nature Methods: Light-sheet Fluorescence Microscopy - Method of the Year 2014 Just about everyone who has examined fluorescent samples under the microscope is aware of the constant struggle to have enough signal to see the labeled structures while also avoiding fluorophore bleaching. What may be less apparent, at least to those who image bright, robust or fixed samples, is how stressful and potentially toxic to living cells and tissues it is to illuminate them with high-intensity light. https://www.leica-microsystems.com/science-lab/nature-methods-light-sheet-fluorescence-microscopy-method-of-the-year-2014/ Wed, 14 Jan 2015 17:24:00 +0000 https://www.leica-microsystems.com/14858 Confocal Microscopy Fluorescence Microscopy Influencing Factors and Applicability of the Viability EMA-qPCR for a Detection and Quantification of Campylobacter Cells from Water Samples In recent years, increasing numbers of human campylobacteriosis cases caused by contaminated water have been reported. As the culture-based detection of Campylobacter is time consuming and can yield false-negative results, the suitability of a quantitative real-time PCR method in combination with an ethidium monoazide pretreatment of samples (EMA-qPCR) for the rapid, quantitative detection of viable Campylobacter cells from water samples was investigated. https://www.leica-microsystems.com/science-lab/influencing-factors-and-applicability-of-the-viability-ema-qpcr-for-a-detection-and-quantification-of-campylobacter-cells-from-water-samples/ Tue, 06 Jan 2015 11:12:00 +0000 https://www.leica-microsystems.com/13917 Confocal Microscopy Live-Cell Imaging Analysis of Autofluorescence in Polymorphonuclear Neutrophils: A New Tool for Early Infection Diagnosis Diagnosing bacterial infection (BI) remains a challenge for the attending physician. An ex vivo infection model based on human fixed polymorphonuclear neutrophils (PMNs) gives an autofluorescence signal that differs significantly between stimulated and unstimulated cells. We took advantage of this property for use in an in vivo pneumonia mouse model and in patients hospitalized with bacterial pneumonia. https://www.leica-microsystems.com/science-lab/analysis-of-autofluorescence-in-polymorphonuclear-neutrophils-a-new-tool-for-early-infection-diagnosis/ Wed, 29 Oct 2014 12:21:00 +0000 https://www.leica-microsystems.com/13795 Super-Resolution Video Interview with Stefan Hell, the Inventor of Super-Resolution Professor Stefan Hell is director at the Max Planck Institute for Biophysical Chemistry and head of the department of NanoBiophotonics in Goettingen and widely considered as the father of super-resolution. His inventions of 4Pi and STED microscopy were turned into the first commercial super-resolution microscopes available by Leica Microsystems in 2004 and 2007. https://www.leica-microsystems.com/science-lab/video-interview-with-stefan-hell-the-inventor-of-super-resolution/ Wed, 08 Oct 2014 18:14:00 +0000 Prof. Dr. Dr. h.c. Stefan Hell, Dipl. oec.-troph. Anja Schué, PhD Isabelle Köster https://www.leica-microsystems.com/14080 Fluorescence Microscopy Live-Cell Imaging Spectral and Structural Comparison Between Bright and Dim Green Fluorescent Proteins in Amphioxus The cephalochordate Amphioxus naturally co-expresses fluorescent proteins (FPs) with different brightness, which thus offers the rare opportunity to identify FP molecular feature/s that are associated with greater/lower intensity of fluorescence. Here, we describe the spectral and structural characteristics of green FP (bfloGFPa1) with perfect (100%) quantum efficiency yielding to unprecedentedly-high brightness, and compare them to those of co-expressed bfloGFPc1 showing extremely-dim brightness due to low (0.1%) quantum efficiency. https://www.leica-microsystems.com/science-lab/spectral-and-structural-comparison-between-bright-and-dim-green-fluorescent-proteins-in-amphioxus/ Thu, 28 Aug 2014 15:54:00 +0000 https://www.leica-microsystems.com/13839 Super-Resolution Super-resolution Molecular and Functional Imaging of Nanoscale Architectures in Life and Materials Science Super-resolution (SR) fluorescence microscopy has been revolutionizing the way in which we investigate the structures, dynamics, and functions of a wide range of nanoscale systems. In this review, I describe the current state of various SR fluorescence microscopy techniques along with the latest developments of fluorophores and labeling for the SR microscopy. https://www.leica-microsystems.com/science-lab/super-resolution-molecular-and-functional-imaging-of-nanoscale-architectures-in-life-and-materials-science/ Mon, 07 Jul 2014 11:45:00 +0000 https://www.leica-microsystems.com/13103 Super-Resolution A New Filtering Technique for Removing Anti-Stokes Emission Background in Gated CW-STED Microscopy Stimulated emission depletion (STED) microscopy is a prominent approach of super-resolution optical microscopy, which allows cellular imaging with so far unprecedented unlimited spatial resolution. The introduction of time-gated detection in STED microscopy significantly reduces the (instantaneous) intensity required to obtain sub-diffraction spatial resolution. https://www.leica-microsystems.com/science-lab/a-new-filtering-technique-for-removing-anti-stokes-emission-background-in-gated-cw-sted-microscopy/ Tue, 25 Mar 2014 20:34:00 +0000 https://www.leica-microsystems.com/12287 Fluorescence Microscopy Quantitative Imaging Live-Cell Imaging Novel Fluorescent Carbonic Nanomaterials for Sensing and Imaging Small brightly fluorescent carbon nanoparticles have emerged as a new class of materials important for sensing and imaging applications. We analyze comparatively the properties of nanodiamonds, graphene and graphene oxide ‘dots’, of modified carbon nanotubes and of diverse carbon nanoparticles known as ‘C-dots’ obtained by different methods. https://www.leica-microsystems.com/science-lab/novel-fluorescent-carbonic-nanomaterials-for-sensing-and-imaging/ Thu, 16 Jan 2014 11:53:00 +0000 https://www.leica-microsystems.com/11693 Confocal Microscopy Live-Cell Imaging Super-Resolution Neuroscience Fluorescence Microscopy Live-Cell Imaging Evolves to Find New Niches Since its introduction in the 1600s, improvements in microscope technology have continually broadened the types of cells and cellular processes that can be studied. Advances in automation have made this already-simple tool faster and more capable, and time-lapse imaging reveals function and dynamics in addition to structure. Live-cell imaging has enabled us to witness incredible moments in biology in unprecedented detail. Even embryogenesis – the process of cell division and cellular differentiation that occurs at the earliest stages of life – has recently been captured. https://www.leica-microsystems.com/science-lab/live-cell-imaging-evolves-to-find-new-niches/ Mon, 25 Nov 2013 10:15:00 +0000 https://www.leica-microsystems.com/10106 Confocal Microscopy Stereo Microscopy Fluorescence Microscopy Organ Regeneration: An Unlikely Fish Tale Spectacular discoveries in cardiac tissue regeneration are rapidly moving researchers closer to the goal of harnessing regenerative techniques to repair the human heart. Only eleven years ago, Dr. Kenneth Poss, Professor of Cell Biology at Duke University and an Early Career Scientist of the Howard Hughes Medical Institute, published the first research to clearly visualize an example of cardiac tissue regeneration using fluorescence microscopy. https://www.leica-microsystems.com/science-lab/organ-regeneration-an-unlikely-fish-tale/ Thu, 20 Jun 2013 08:01:00 +0000 PhD Katharine H. Hendrix https://www.leica-microsystems.com/9492 Live-Cell Imaging Fluorescence Microscopy Quantitative Imaging Imaging Enzymes at Work For the understanding of functions of proteins in biological and pathological processes, reporter molecules such as fluorescent proteins have become indispensable tools for visualizing the location of these proteins in intact animals, tissues, and cells. For enzymes, imaging their activity also provides information on their function or functions, which does not necessarily correlate with their location. Metabolic mapping enables imaging of activity of enzymes. https://www.leica-microsystems.com/science-lab/imaging-enzymes-at-work/ Fri, 05 Apr 2013 14:27:00 +0000 https://www.leica-microsystems.com/9410 Stereo Microscopy Fluorescence Microscopy Stereo microscopes with TripleBeam Technology Especially in fluorescence microscopy, excitation light is friend and foe in one. On the one hand, energy-rich excitation via a specific light wavelength of the fluorochrome resulting in a bright positive fluorochrome signal is highly welcome. On the other hand, "noise" caused by reflections of excitation light passing through the surfaces of optical elements needs to be extremely slight to generate a perfect black background. This relation is described as "signal-to-noise ratio", which is highly relevant for differentiating optically between fluorescence positive and negative cells. https://www.leica-microsystems.com/science-lab/stereo-microscopes-with-triplebeam-technology/ Tue, 02 Apr 2013 12:35:00 +0000 Björn Fuchs https://www.leica-microsystems.com/9043 Super-Resolution STED and GSDIM: Diffraction Unlimited Resolution for all Types of Fluorescence Imaging This article gives an overview of two different types of superresolution techniques. Stimulated emission depletion (STED) microscopy is a versatile and fast method that is based on point scanning microscopy – usually an extension of a confocal microscope. Ground state depletion imaging (GSDIM) is a parallel recording widefield approach that explores inherent switching of fluorochromes and typically comes with a TIRF microscope. The two methods use very different approaches to reach the same goal: to see more details in light microscopes than possible when diffraction limited. https://www.leica-microsystems.com/science-lab/sted-and-gsdim-diffraction-unlimited-resolution-for-all-types-of-fluorescence-imaging/ Thu, 28 Feb 2013 23:00:00 +0000 https://www.leica-microsystems.com/7981 Confocal Microscopy The White Confocal Modern biomedical research is currently dominated by imaging and measuring with optical microscopes. One branch of the microscopy technology is confocal microscopy. For correlation purposes, multiparameter fluorescence imaging is particularly of unique interest. This article is concerned with the spectral performance of the various modules in a confocal point-scanning microscope ("True Confocal System"), and how these modules have evolved to allow for tunability and flexibility in excitation and emission collection in multiple bands (channels). https://www.leica-microsystems.com/science-lab/the-white-confocal/ Tue, 19 Feb 2013 23:00:00 +0000 https://www.leica-microsystems.com/6673 Basics in Microscopy Video Tutorial: How to Align the Bulb of a Fluorescence Lamp Housing The traditional light source for fluorescence excitation is a fluorescence lamp housing with mercury burner. A prerequisite for achieving bright and homogeneous excitation is the correct centering and alignment of the bulb inside the housing. This video tutorial presents an easy-to-copy way to align the mercury bulb in a fluorescence lamp housing. https://www.leica-microsystems.com/science-lab/video-tutorial-how-to-align-the-bulb-of-a-fluorescence-lamp-housing/ Sun, 19 Aug 2012 22:00:00 +0000 Beate Braun, Dr. Werner Wittke https://www.leica-microsystems.com/6675 Basics in Microscopy Video Tutorial: How to Change the Bulb of a Fluorescence Lamp Housing When applying fluorescence microscopy in biological applications, a lamp housing with mercury burner is the most common light source. This video tutorial shows how to change the bulb of a traditional fluorescence lamp housing. https://www.leica-microsystems.com/science-lab/video-tutorial-how-to-change-the-bulb-of-a-fluorescence-lamp-housing/ Sun, 19 Aug 2012 22:00:00 +0000 Beate Braun, Dr. Werner Wittke https://www.leica-microsystems.com/6600 Confocal Microscopy Live-Cell Imaging Quantitative Imaging Label-free FLIM Many biological samples exhibit autofluorescence. Its often broad spectra can interfere with fluorescent labeling strategies. This application letter demonstrates how autofluorescence can serve as an intrinsic contrast in fluorescence lifetime imaging microscopy (FLIM) resulting in multi-color image stacks. https://www.leica-microsystems.com/science-lab/label-free-flim/ Thu, 09 Aug 2012 22:00:00 +0000 Dr. Constantin Kappel https://www.leica-microsystems.com/6602 Confocal Microscopy Live-Cell Imaging Quantitative Imaging FRET with FLIM FLIM combines lifetime measurements with imaging: lifetimes obtained for each image pixel are color-coded to produce additional image contrast. Thus, FLIM delivers information about the spatial distribution of a fluorescent molecule together with information about its biochemical status or nano-environment. A typical application of FLIM is FLIM-FRET. FRET is a well-established technique to study molecular interactions. It scrutinizes protein binding and estimates intermolecular distances on an Angström scale as well. https://www.leica-microsystems.com/science-lab/fret-with-flim/ Tue, 07 Aug 2012 22:00:00 +0000 Dr. Constantin Kappel https://www.leica-microsystems.com/6609 Confocal Microscopy Quantitative Imaging Fluorescence Correlation Spectroscopy Fluorescence correlation spectroscopy (FCS) measures fluctuations of fluorescence intensity in a sub-femtolitre volume to detect such parameters as the diffusion time, number of molecules or dark states of fluorescently labeled molecules. The technique was independently developed by Watt Webb and Rudolf Rigler during the early 1970s. https://www.leica-microsystems.com/science-lab/fluorescence-correlation-spectroscopy/ Thu, 02 Aug 2012 22:00:00 +0000 Dr. Constantin Kappel https://www.leica-microsystems.com/6499 Fluorescence Microscopy Live-Cell Imaging Widefield Microscopy Digital Camera Technologies for Scientific Bio-Imaging This four-part series of articles published in Microscopy and Analysis covers the factors to consider in choosing a camera among CCD, EMCCD, and scientific-grade CMOS camera technologies for biological imaging applications. The differences among the sensor architectures and the impact of parameters such as pixel size, noise, and QE on signal-to-noise performance, image quality, and Nyquist sampling are considered. https://www.leica-microsystems.com/science-lab/digital-camera-technologies-for-scientific-bio-imaging/ Wed, 18 Jul 2012 22:00:00 +0000 https://www.leica-microsystems.com/6417 Image Processing for Widefield Microscopy Fluorescence microscopy is a modern and steadily evolving tool to bring light to current cell biological questions. With the help of fluorescent proteins or dyes it is possible to make discrete cellular components visible in a highly specific manner. A prerequisite for these kinds of investigations is a powerful fluorescence microscope. One special aim is the three-dimensional illustration of a structure to get an impression of full plasticity. This poses a certain problem for the experimenter using a classical light microscope. https://www.leica-microsystems.com/science-lab/getting-sharper-3d-images-of-thick-biological-specimens-with-widefield-microscopy/ Wed, 04 Jul 2012 22:00:00 +0000 Dr. Christoph Greb https://www.leica-microsystems.com/5945 TIRF Microscopy Controlling the TIRF Penetration Depth is Mandatory for Reproducible Results The main feature of total internal reflection fluorescence (TIRF) microscopy is the employment of an evanescent wave for the excitation of fluorophores instead of using direct light. A property of the evanescent wave, which arises from the glass/water or glass/specimen interface, is that its propagation in z-direction gradually degrades, limiting its penetration depth into the specimen to some hundred nanometers. https://www.leica-microsystems.com/science-lab/controlling-the-tirf-penetration-depth-is-mandatory-for-reproducible-results/ Tue, 24 Apr 2012 22:00:00 +0000 Dr. Thomas Veitinger https://www.leica-microsystems.com/5899 Quantitative Imaging Quantitative Fluorescence Seeing is believing – and measuring is knowing. Microscopes generate images that are not only used for illustration, but are also subject to quantification. More advanced techniques use illumination patterns (without image formation) or do not generate an image at all – but are still microscopical techniques. These F-techniques are becoming increasingly important in current biosciences. https://www.leica-microsystems.com/science-lab/quantitative-fluorescence-1/ Wed, 18 Apr 2012 22:00:00 +0000 https://www.leica-microsystems.com/5890 Fluorescence Microscopy Basics in Microscopy Basic Principles of Luminescence There are a lot of light-emitting processes occurring in nature. Luminescence is an umbrella term for those kinds of events where light emission is not the result of high temperatures. This article depicts the different forms of luminescences and goes into detail in the case of fluorescence. Relevant technical terms describing a fluorochrome, like quenching, bleaching or quantum yield, are explained in the second part of the article to give detailed insights into basic characteristics of fluorescent molecules. https://www.leica-microsystems.com/science-lab/basic-principles-of-luminescence/ Mon, 09 Apr 2012 22:00:00 +0000 Dr. Christoph Greb https://www.leica-microsystems.com/5403 TIRF Microscopy Live-Cell Imaging Widefield Microscopy Total Internal Reflection Fluorescence (TIRF) Microscopy Total internal reflection fluorescence (TIRF) is a special technique in fluorescence microscopy developed by Daniel Axelrod at the University of Michigan, Ann Arbor in the early 1980s. TIRF microscopy delivers images with an outstandingly high axial resolution below 100 nm. This allows the observation of membrane-associated processes. https://www.leica-microsystems.com/science-lab/total-internal-reflection-fluorescence-tirf-microscopy/ Sun, 11 Mar 2012 23:00:00 +0000 Wymke Ockenga https://www.leica-microsystems.com/5405 Live-Cell Imaging TIRF Microscopy Widefield Microscopy Applications of TIRF Microscopy in Life Science Research The special feature of TIRF microscopy is the employment of an evanescent field for fluorophore excitation. Unlike standard widefield fluorescence illumination procedures with arc lamps, LEDs or lasers, the evanescent field only penetrates the specimen by about 100 nm starting from the coverslip/medium interface. https://www.leica-microsystems.com/science-lab/applications-of-tirf-microscopy-in-life-science-research/ Sun, 11 Mar 2012 23:00:00 +0000 Wymke Ockenga, Dr. Thomas Veitinger https://www.leica-microsystems.com/5256 Fluorescence Microscopy Fluorescent Proteins - From the Beginnings to the Nobel Prize Fluorescent proteins are the fundament of recent fluorescence microscopy and its modern applications. Their discovery and consequent development was one of the most exciting innovations for life sciences in the last century and the starting point of the deciphering of numberless natural phenomena. https://www.leica-microsystems.com/science-lab/fluorescent-proteins-from-the-beginnings-to-the-nobel-prize/ Thu, 16 Feb 2012 23:00:00 +0000 Dr. Christoph Greb https://www.leica-microsystems.com/5082 Confocal Microscopy Quantitative Imaging FLCS – Advances in Fluorescence Correlation Spectroscopy The characterization of substances at the single molecule level has become part of the standard repertoire of scientific research institutes. One of the most common methods is Fluorescence Correlation Spectroscopy (FCS), which can be used to examine the dynamics and concentration of fluorescent molecules in solution. https://www.leica-microsystems.com/science-lab/flcs-advances-in-fluorescence-correlation-spectroscopy/ Wed, 14 Dec 2011 23:00:00 +0000 Dr. Andreas Bülter, Dr. Andrea Bleckmann, Uwe Ortmann https://www.leica-microsystems.com/4811 Confocal Microscopy Quantitative Imaging Fluorescence Recovery after Photobleaching (FRAP) and its Offspring FRAP (Fluorescence recovery after photobleaching) can be used to study cellular protein dynamics: For visualization the protein of interest is fused to a fluorescent protein or a fluorescent dye. A region of interest (ROI) can be monitored applying a high amount of light to bleach the fluorescence within the ROI. The following illumination with low light conditions provides insight into the redistribution of molecules via recovery of fluorescence. https://www.leica-microsystems.com/science-lab/fluorescence-recovery-after-photobleaching-frap-and-its-offspring/ Wed, 23 Nov 2011 07:19:37 +0000 Dr. Jan Schröder https://www.leica-microsystems.com/4356 Confocal Microscopy Quantitative Imaging Förster Resonance Energy Transfer (FRET) The Förster Resonance Energy Transfer (FRET) phenomenon offers techniques that allow studies of interactions in dimensions below the optical resolution limit. FRET describes the transfer of the energy from an excited state of a donor molecule to an acceptor molecule. Unlike absorption or emission of photons, FRET is a non-radiative energy exchange and consequently not a variation of light-matter interactions. https://www.leica-microsystems.com/science-lab/foerster-resonance-energy-transfer-fret/ Wed, 09 Nov 2011 09:45:00 +0000 Gabriele Burger https://www.leica-microsystems.com/4182 Fluorescence Microscopy Basics in Microscopy An Introduction to Fluorescence Fluorescence is widely used in microscopy and an important tool for observing the distribution of specific molecules. Most molecules in cells do not fluoresce. They therefore have to be marked with fluorescing molecules called fluorochromes. https://www.leica-microsystems.com/science-lab/an-introduction-to-fluorescence/ Tue, 31 May 2011 13:29:00 +0000 Wymke Ockenga https://www.leica-microsystems.com/4186 Basics in Microscopy Fluorescence Microscopy Photo Effects of Light Molecules and atoms can exist in different quantum states. These states are dedicated to different energy levels; the quantum state with the lowest energy is called the ground state. Every state of greater energy is an excited state of the quantum mechanical system. Electrons can be excited by an exogenous energy source and switch to a higher energy level, changing the quantum state of the molecule or atom. The electrons are often referred to as being brought to a state of higher energy. https://www.leica-microsystems.com/science-lab/photo-effects-of-light/ Mon, 30 May 2011 15:13:00 +0000 Wymke Ockenga https://www.leica-microsystems.com/4188 Fluorescence Microscopy Basics in Microscopy Widefield Microscopy Fluorescence in Microscopy Fluorescence microscopy is a special form of light microscopy. It uses the ability of fluorochromes to emit light after being excited with light of a certain wavelength. Proteins of interest can be marked with such fluorochromes via antibody staining or tagging with fluorescent proteins. https://www.leica-microsystems.com/science-lab/fluorescence-in-microscopy/ Wed, 27 Apr 2011 15:47:00 +0000 Wymke Ockenga https://www.leica-microsystems.com/2561 Confocal Microscopy Multiphoton Microscopy Live-Cell Imaging Stem Cell Biology in Cancer Research The comprehension of stem cell biology and its molecular basis is now acquiring paramount importance in cancer research. The need to look at a single, possibly living, cell makes fluorescence microscopy and confocal microscopy invaluable allies in the study of stem cells. https://www.leica-microsystems.com/science-lab/stem-cell-biology-in-cancer-research/ Thu, 22 Apr 2010 22:00:00 +0000 Laura Furia, Angelo Cicalese, Ilaria Rancati, Isabella Ponzanelli, Paolo Bianchini, Prof. Alberto Diaspro, Mario Faretta https://www.leica-microsystems.com/9447 Stereo Microscopy Detection and Characterization of Hepatic Engraftment of Embryonic Stem Derived Cells by Fluorescent Stereomicroscopy Embryonic stem (ES) cells have been investigated as a potential replacement therapy for failed organs, such as the liver. However, detection of hepatic engraftment from candidate stem cells has been difficult due to low engraftment efficiency. Previous detection methods required that the graft be processed by molecular and/or immunohistochemical techniques, limiting further functional studies. This study evaluated the use of three-dimensional fluorescent stereomicroscopy for gross detection of ES cell derived hepatic engraftment. https://www.leica-microsystems.com/science-lab/detection-and-characterization-of-hepatic-engraftment-of-embryonic-stem-derived-cells-by-fluorescent-stereomicroscopy/ Wed, 15 Aug 2007 13:23:00 +0000 https://www.leica-microsystems.com/10023 Quantitative Imaging Fluorescence Recovery after Photobleaching with the Leica TCS SP2 Among all photobleaching experiments which have been described, fluorescence recovery after photobleaching (FRAP) is the most popular. It employs irradiation of a fluorophore in a living sample with a short laser pulse to degrade it and thereby abolish fluorescence followed by time-resolved image recording of the sample. https://www.leica-microsystems.com/science-lab/fluorescence-recovery-after-photobleaching-with-the-leica-tcs-sp2/ Sun, 15 Aug 2004 19:15:00 +0000 Dr. Constantin Kappel, Professor Dr. Roland Eils https://www.leica-microsystems.com/9682 Fluorescence Microscopy Multi-Wavelength Epi-Illumination in Fluorescence Microscopy Fluorescence is a process where a substance after having absorbed light (photons) emitts a radiation the wavelength (colour) of which is longer than that of the absorbed light, and where this emission stops immediately after cessation of the excitation. This phenomenon is the basic element of fluorescence microscopy and its application. https://www.leica-microsystems.com/science-lab/multi-wavelength-epi-illumination-in-fluorescence-microscopy/ Sat, 01 Dec 2001 15:35:00 +0000 Professor em. Johan Sebastiaan Ploem, Dr. Friedrich Walter