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Glossary terms about Photon

Elementary quantity of radiant energy (quantum) whose value is equal to the product of Planck’s constant h and the frequency (hz) of the electromagnetic radiation.

6 pages mention Photon

Components of the confocal microscope
Frequency doubled DPSS 488 nm blue, 532 nm green, 561 nm yellow/green Multiphoton tunable lasers. 
Detection parameters
Gain (also called HV or high voltage) is a relative measure of the amplification one applies to the photon detection system. 
Fluorescence microscopy
When excited, the fluorochrome absorbs photons leading to the shuttling of electrons to higher energy states (see the Jablonski diagram). 
Practical image acquisition
Photobleaching results when a fluorescent molecule is in its excited semi-stable state and is then hit by a second photon causing permanent damage to the molecule. 
Scanning and resolution
As the light hits the specimen, fluorescence photons are emitted and some enter the objective lens. 
Sequential and simultaneous
When DAPI is excited by the appropriate wavelength of light, the molecule enters a transient excited state for a short period of time (the "lifetime" which, for many probes used in confocal microscopy, is usually between 1 and 10 nanoseconds), before it may decay back to some resting energy state and emitting the previously absorbed energy as a photon of light.