Fluorescent moiety

The nondestructive introduction of a fluorescent label would provide the molecule with a nonradioactive fluorophore, yet would preserve the option for direct radiolabelling of the fluorescent moiety with 125Iodine. This approach was pioneered by Nagasawa et al. (5) who reacted native or /V-desulfated heparins with a fluorescein isothiocyanate (FITC). The resulting degree of labelling was low... 

Labeling of the RNA sample with a fluorescent nucleotide can be done either directly or indirecdy. In a direct labeling, one of the nucleotides (usually dUTP or dCTP) has a fluorescent moiety (either Cy3 or Cy5)... 

Macro domains of micrometer size have been reported when using an ordinary microscope. The typical procedure is to use 2% of a fluorescent lipid analog, which renders visible a domain pattern. This, of course, assumes that the fluorescence moiety has no effect on the assembly structure. There is (generally) no information about the thickness of the domains. The shapes of domains are varied, and very complex (circular or near-circular domains, parallel stripes, or more irregular, wormlike, or similar kinds of structures). 

Approaches used to the development of LC materials with valuable luminescent properties include the synthesis of rod-like mesogens from fluorescent moieties, e.g. benzopyrans, " and discotic LCs with a fluorescent polyaromatic core. ... 

To make these substrates suitable for biological assays, the introduction of functional groups that can be traced with the proper analytical techniques is essential. The use of radio-, fluorescent-, and biotin-labeled lipidated peptides has been reported. The synthesis of fluorescent substrates is chemically straightforward and allows for production of larger quantities than the enzymatic synthesis used for radiolabeled peptides and is thus preferred over the use of radioactive compounds. [1 21] Common fluorescent probes can be introduced by conjugation to a free functional group present in the peptide. The fluorescent moiety is... 

Some analytes, such as riboflavin (vitamin B2)16 and polycyclic aromatic compounds (an important class of carcinogens), are naturally fluorescent and can be analyzed directly. Most compounds are not luminescent. However, coupling to a fluorescent moiety provides a route to sensitive analyses. Fluorescein is a strongly fluorescent compound that can be coupled to many molecules for analytical purposes. Fluorescent labeling of fingerprints is a powerful tool in forensic analysis.17 Sensor molecules whose luminescence responds selectively to a variety of simple cations and anions are available.18 Ca2+ can be measured from the fluorescence of a complex it forms with a derivative of fluorescein called calcein. 

The use of biotinylated antibodies provides perhaps the greatest versatility and sensitivity of all methods The affinity of biotin for avidin or the more usually used streptavidm is very high, and the latter can be conjugated to radioisotope, fluorescent moiety, or enzyme Again, the basic procedures are the same as outlined for l25I-labeled antibodies with the additional steps required for streptavidin binding and subsequent incubation with enzyme substrate (see also Chapters 17 and 18)... 

Green fluorescent protein is commonly used for energy-transfer experiments (Baubet etal. 2000). The fluorescent moiety of GFP protein is the Ser-Tyr-Gly derived chromophore. GFP can be expressed in a variety of cells where it becomes fluorescent, can be fused to a host... 

In this method, specific functional groups reagents containing a marker - halogens, radioactive isotopes, fluorescent moieties... 

A new synthetic route towards naphthyl xylosides was performed on solid support. Pure xylosides were obtained in 6-42% overall yield from the amino-methylated resin [84, 85], Similarly, p-o-xylopyranosides bearing a fluorescent moiety as a probe for proteoglycan biosynthesis [83], bis-xylosylated dihydrox-ynaphthalenes [86] and 2-naphthyl-l-thio-P-o-xylopyranosides were also prepared and these compounds have exhibited a strong pruning of GAG chains biosynthesis [87]. 

Fig. 12 (a) Cross-sectional view of a microchip, heating element, and thermocouples, (b) Diagram of the microchip used for on-chip proteolytic reactions, separations, and post-column labeling for generating fluorescent moieties. The fluid reservoirs are (1) substrate, (2) enzyme, (i) buffer, (4) sample waste, (5) NDA, and (6) waste. Reproduced from [134]... 

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