Bioluminescence | Bioluminescence

Key Words: BRET, fluorescence, fluorophore, live-cell imaging, photomultiplier

Definition:Bioluminescence is light created by a living organism

TECHNOLOGY:

While the effect of bioluminescence is similar to that of fluorescence the processes leading to the generation of light are different. Fluorescence results from the emission of a photon as a result of excitation of an electron. Bioluminescence results in the emission of a photon through a chemical reaction within an organism (for example, in the firefly, jack o'lantern mushroom). Light is produced by the oxidation of a luciferin catalysed by a luciferase and often mediated by ATP and/ or calcium ions (luciferin and luciferase are non-specific terms for a substrate and enzyme involved in light producing reactions).

APPLICATIONS:

Bioluminescence can be used to measure intracellular cofactors and ion concentrations (Ca2+, K+, ATP, NADH). Luciferase reactions are employed in the food and pharmaceutical industries to detect living contaminants, in forensics to detect traces of blood, and in research environments - luciferase can be transfected into living cells and is widely used as a gene reporter. Bioluminescence reactions avoid the need for excitation light and associated phototoxicity, and avoid triggering background autofluorescence in living cells.

MICROSCOPE CONFIGURATION:

The microscope configuration will depend on the application. The main limitation is the brief intensity of emitted light. This requires high N.A. objectives and photomultiplier for the detection and measurement of photons. As with fluorescence, confocal imaging provides improved resolution compared with widefield techniques and provides opportunities for 3-D imaging.

RECOMMENDED SYSTEM:

This will depend greatly on the applications, for fast multidimensional ion measurements, Nikon's Ti-E inverted microscope with LiveScan Sweptfield confocal system offers versatile high resolution confocal imaging.