training for advanced research


Glossary terms about Wavelength

The distance on a periodic wave between two successive points at which the phase is the same. It is represented by the symbol (λ) and is usually expressed in nanometres and commonly refers to the colour of light.

18 pages mention Wavelength

Collecting Z stacks
The thickness of an optical section is predominantly determined by the numerical aperture of the objective and the diameter of the confocal pinhole (and, to a lesser extent, the wavelength of the light. 
Components of the confocal microscope
Confocal microscopy
The light source is a laser – or more than one to give a range of wavelengths. 
Fluorescence microscope
Fluorescence microscopy
Each fluorochrome has a specific set of spectra so that optimal excitation and detection can only be achieved within a small bandwidth of light wavelengths. 
Image acquisition (single scan)
Optical microscopy uses visible light, and its performance is inherently limited by the wavelength of light. 
Multichannel imaging
Objective lens - magnification versus resolution
Pinhole - effects of resolution
Pixel arrays - dimensions versus pixel size
Practical image acquisition
This will often require lowering the illuminating laser power or using a laser wavelength that minimises any photodamage. 
Scan speed - pixel dwelling, saturation
Scanning and resolution
In the table below you can see the zoom at which you reach Nyquist sampling for this particular microscope, at the stated NA and wavelength
Sequential and simultaneous
However, when attempting to image multiple fluorescent probes in the same sample, it is essential that excitation laser wavelengths and emission filters are carefully chosen. 
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Transmitted light microscope