Bioluminescence centered at about 490 mn occurs in the bacterial luciferase system upon the oxidation of reduced flavin mononucleotide by molecular oxygen. Although excited FMN is the apparent candidate for the emitting molecule, the color of its fluorescence, which is centered at about 525 nm, does not correspond to that of the bioluminescence. In the experiments reported here flavins differin...

Bioluminescence imaging became a widely used technique for noninvasive study of biological processes in small animals. Bioluminescent probes with emission in near-infrared (NIR) spectral region confer the advantage of having deep tissue penetration capacity. However, there are a very limited number of currently available luciferases that exhibit NIR bioluminescence. Here, we engineered two nove...

Firefly luciferase catalyzes the emission of light from luciferin in the presence of oxygen and adenosine triphosphate. This bioluminescence is commonly employed in imaging mode to monitor tumor growth and treatment responses in vivo. A potential concern is that, since solid tumors are often hypoxic, either constitutively and/or as a result of treatment, the oxygen available for the bioluminesc...

Portable light-baffled underwater photometers have been designed for the measurement of dinoflagellate bioluminescence by day and night. Maximal light emission is obtained by mechanical stimulation in a defined volume. The pump which stimulates the dinoflagellates also constantly replenishes the sample volume so that continuous measurements are possible. Evidence for both diurnal variation and ...

All biological samples emit ultra-low intensity light without any external stimulation. Recently, scientific communities have paid particular attention to this phenomenon, known as ultra-weak photon emission (UPE). UPE has been introduced in the literature as an alternative for biophoton, low-level chemiluminescence and ultra-weak bioluminescence, while it differs from ordinary bioluminescence,...

Bioluminescence (light production) and fluorescence (re-emission of absorbed radiation as light) are found in an unaccountably diverse array of marine organisms, where their functions are largely unknown. Here we report a deep-sea siphonophore that twitches glowing lures to attract fish. This is rare evidence of bioluminescence used for prey attraction among nonvisual marine organisms. The lure...

A 5,5-d2 -luciferin was prepared to measure isotope effects on reactions of two intermediates in firefly bioluminescence: emission by oxyluciferin and elimination of a putative luciferyl adenylate hydroperoxide to dehydroluciferin. A negligible isotope effect on bioluminescence provides further support for the belief that the emitting species is the keto-phenolate of oxyluciferin and rules out ...

After Luciola praeusta Kiesenwetter 1874, Asymmetricata circumdata (Motschulsky) is the second Indian species of firefly identified recently. Here we present steady-state and time-resolved measurements of bioluminescence emissions of male specimens of this new-found species. Steady-state spectra recorded in a high-resolution spectrometer show the peak wavelength at 570 nm, while the same on a c...

Animals in the lower mesopelagic zone (600-1,000 m depth) of the oceans have converged on two major strategies for camouflage: transparency and red or black pigmentation [1]. Transparency conveys excellent camouflage under ambient light conditions, greatly reducing the conspicuousness of the animal's silhouette [1, 2]. Transparent tissues are seldom perfectly so, resulting in unavoidable intern...