Signal-to-Noise

Stereomicroscopes 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.



Stereo Microscopy

Apr 02, 2013

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Sensors for True Confocal Scanning



In this article, advantages and disadvantages of different types of sensors for single point true confocal scanning devices are discussed. Traditionally, photomultiplier tubes have been employed in such systems. For some cases, avalanche photodiodes have proven to fit best. A new development uniting vacuum and silicon technology has led to chimeric sensors, called hybrid detectors (HyD). They benefit from both technologies.



Confocal Microscopy

Aug 23, 2012

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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.



TIRF Microscopy

Apr 25, 2012

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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.



TIRF Microscopy

Mar 12, 2012

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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.



Live-Cell Imaging

Mar 12, 2012

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