Visible fluorescent proteins

Visser NV, Borst JW, Hink MA, van Hoek A, Visser AJWG (2005) Direct observation of resonance tryptophan-to-chromophore energy transfer in visible fluorescent proteins. Biophys Chem 116 207-212... 

BRET [31, 32]), lock-in detection techniques exploiting optical switches [33], and schemes for alternating D/A excitation (ALEX [34]). The increased attention to quantitative FRET imaging encompasses the use of polarization [35-39], the perennial issue of calibration and standards [40-44], and practical guides to operational principles and protocols ([45, 46] and other references above). The fundamental distinctions between the requirements for live and fixed cell imaging cannot be overemphasized, as is exemplified in a report of erroneous FRET determinations with visible fluorescent proteins (VFPs) in fixed cells [47],... 

Visible fluorescent proteins from jellyfish and corals (VFPs) la. Spectral variants lb. Dual-VFP or VFP-luciferase constructs for sensing ions, pH, covalent modification,... lc. Photoactivatable, photoconvertible, 238 27 + ... 

The fast, sensitive, reliable, and reproducible detection of (bio)molecules including quantification as well as biomolecule localization, the measurement of their interplay with one another or with other species, and the assessment of biomolecule function in bioassays as well as in vitro and in vivo plays an ever increasing role in the life sciences. The vast majority of applications exploit extrinsic fluorophores like organic dyes, fluorescent proteins, and also increasingly QDs, as the number of bright intrinsic fluorophores emitting in the visible and NIR is limited. In the near future, the use of fluorophore-doped nanoparticles is also expected to constantly increase, with their applicability in vivo being closely linked to the intensively discussed issue of size-related nanotoxicity [88]. 

FIA Fluorescence immunoassay uses a fluorescent tag on the antibody or antigen. Fluorescent labels absorb light of one wavelength and reemit it at another wavelength. The label is excited by UV and emits visible light. Common fluorescent labels are fluorescein, Texas red, and GFP (green fluorescent protein). 

GFP Green fluorescent protein comes from the jellyfish Aequorea victoria. It fluoresces green, which is of puzzling utility to the jellyfish but of great use to scientists because it can act as a reporter molecule or can be used to make fusion proteins visible. Outdoing the jellyfish, molecular biologists have created GFP analogs that fluoresce in different colors (BFP, CFP, and YFP). 

Figure 4.38. Nuclear Localizatiou of a Steroid Receptor. (A) The receptor, made visible by attachment of the green fluorescent protein, is located predominantly in the cytoplasm of the cultured cell. (B) Subsequent to the addition of corticosterone (a glucocorticoid steroid), the receptor moves into the nucleus. [Courtesy of Professor William B. Pratt/ Department of Pharmacology, University of Michigan.]... 

Figure 2 The Sertoli cell extends from the base of the seminiferous tubule (bottom right) to the lumen (upper left) and has numerous cytoplasmic projections that surround and support germ cells. In this maximum intensity projection of 13 series confocal images, a single Sertoli cell in an intact seminiferous tubule is visible because of green fluorescent protein expression following adenovirus infection. The Sertoli cell nucleus is visible in the basal cytoplasm surrounded by brightfluorescence. The overall length ofthis Sertoli is approximately 100 /xm.

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