Search results
Results from the WOW.Com Content Network
Fluorescence in the life sciences is used generally as a non-destructive way of tracking or analysis of biological molecules by means of the fluorescent emission at a specific frequency where there is no background from the excitation light, as relatively few cellular components are naturally fluorescent (called intrinsic or autofluorescence).
A simplified Jablonski diagram illustrating the change of energy levels.. The principle behind fluorescence is that the fluorescent moiety contains electrons which can absorb a photon and briefly enter an excited state before either dispersing the energy non-radiatively or emitting it as a photon, but with a lower energy, i.e., at a longer wavelength (wavelength and energy are inversely ...
Fluorescence spectroscopy (also known as fluorimetry or spectrofluorometry) is a type of electromagnetic spectroscopy that analyzes fluorescence from a sample.
Biofluorescence is fluorescence emitted by a living organism. Biofluorescence requires an external light source and a biomolecular substance that converts absorbed light into a new one. The fluorescent substance absorbs light at one wavelength, often blue or UV, and emits at another, longer wavelength, green, red, or anything in between.
Micrograph of paper autofluorescing under ultraviolet illumination. The individual fibres in this sample are around 10 μm in diameter.. Autofluorescence is the natural emission of light by biological structures such as mitochondria and lysosomes when they have absorbed light, and is used to distinguish the light originating from artificially added fluorescent markers (fluorophores).
Fluorescence correlation spectroscopy (FCS) is an analysis technique that observes the fluctuation of fluorescence intensity. This analysis is a component of many fluorescence imaging machines and improvements in spatial resolution could improve the sensitivity and range.
Steady-state fluorescence spectra of the DNA nucleosides normalized to their maximum intensity. The fluorescence of all DNA systems in neutral aqueous solution peaks in the near ultraviolet (300-400 nm) when excited around 260 nm. In addition, a long tail, extending all over the visible domain is present in the fluorescence spectrum.
These techniques can be combined with microscopy, to map the intensity (confocal microscopy) or the lifetime (fluorescence-lifetime imaging microscopy) of the photoluminescence across a sample (e.g. a semiconducting wafer, or a biological sample that has been marked with fluorescent molecules). Modulated photoluminescence is a specific method ...