Describe fluorescence microscopy in detail.
Answers
The term fluorescence refers to one type of luminescence. Luminescence, broadly defined, is light emission from a molecule. There are several types of luminescence.
Photoluminescence is when light energy, or photons, stimulate the emission of a photon.
Chemiluminescence, is defined as when chemical energy stimulates the emission of a photon, and this includes bioluminescence, as seen in fire flies and many forms of sea life.
Electroluminescence, is when electrical energy or a strong electric field, stimulates the emission of a photon, such as in some lighting applications.
Fluorescence, specifically, is a type of photoluminescence where light raises an electron to an excited state. The excited state undergoes rapid thermal energy loss to the environment through vibrations, and then a photon is emitted from the lowest-lying singlet exited state. This process of photon emission competes for other non-radiative processes including energy transfer and heat loss.
When the term “fluorescence” is used, the same methods of measurement can typically be applied to any of the above categories of luminescence.
