Christoph Greb, Dr.

Christoph Greb studied cell Biology, Parasitology and Virology at the Philipps University in Marburg. He finished with the diploma thesis “Influence of Galectin-3 on the Oligomerization of Apical Membrane Proteins”. His dissertation has the title “Components and Transport Ways at the Apical Membrane of Polar Ephitelial Cells”. Both of them he wrote at the Institute for Cytobiology and Cytopathology in Marburg, where he was having a postdoc position until November 2011. Scince December 20011 he is writing for the Leica Science Lab as a freelancer.

christoph.greb@gmx.de

Deconvolution

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.

Fluorescence Microscopy

Jul 05, 2012

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Highlighter Proteins and Fluorescent Timers

The term "Highlighter Proteins" combines a group of genetically altered fluorescent proteins with very special attributes: They can be activated from a non fluorescent state, they can change their emission spectrum or they are even able to be switched "on and off" for a lot of times. This behavior is due to some distinct photo physical attributes. At the single molecule level many fluorescent proteins show an intrinsic blinking activity which can be influenced by external illumination.

Fluorescence Microscopy

Jun 20, 2012

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Fluorescent Dyes

A basic principle in fluorescence microscopy is the highly specific visualization of cellular components with the help of a fluorescing agent. This can be a fluorescing protein – for example GFP – genetically linked to the protein of interest. If cloning is impossible – for instance in histologic samples – it is required to use other techniques like immunofluorescence staining to visualize the protein of interest.

Fluorescence Microscopy

Jun 11, 2012

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Fluorescent Proteins – Introduction and Photo Spectral Characteristics

The prospects of fluorescence microscopy changed dramatically with the discovery of fluorescent proteins in the 1950s. The starting point was the detection of the jellyfish Aequorea victoria green fluorescent protein (GFP) by Osamo Shimomura. Hundreds of GFP mutants later, the range of fluorescent proteins reaches from the blue to the red spectrum.

Fluorescence Microscopy

Apr 10, 2012

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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.

Fluorescence Microscopy

Apr 10, 2012

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Protein Transport Processes at the Apical Membrane of Polarized Epithelial Cells

Figure_2_Interaction_of_Galectin-3-DsRed_and_P75-GFP_01.jpg

Due to their special role in organ function and the exchange of biological components some body cells developed certain polarization characteristics. These are reflected in differences of their plasma membrane composition. The essential and fascinating task of polarized protein transport in epithelial cells is to get the right protein into the right membrane.

TIRF Microscopy

Mar 12, 2012

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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.

Fluorescence Microscopy

Feb 17, 2012

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TIRF Microscopy of the Apical Membrane of Polarized Epithelial Cells

Application of TIRF microscopy (Total Internal Reflection Fluorescence) allows the visualization of structures at the apical surface of polarized epithelial cells that have been hidden in conventional fluorescence microscopy images. Hence, the approach reveals new insights into the composition of this characteristic cell pole that elucidate processes in apical protein trafficking.

Live-Cell Imaging

Apr 13, 2011

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