Green fluorescent

LIF is also used witii liquid and solid samples. For example, LIF is used to detect lJO ions in minerals the uranyl ion is responsible for the bright green fluorescence given off by minerals such as autunite and opal upon exposure to UV light [23],... 

Dickson R M, Cubitt A B, Tsien R Y and Moerner W E 1997 On/off blinking and switching behaviour of single molecules of green fluorescent protein Nature 388 355-8... 

Pierce D W, Hom-Booher N and Vale R D 1997 Imaging individual green fluorescent proteins Nature 388 338... 

I. Fluorescein test. Fuse together carefully in a dry test-tube for about 1 minute a few crystals of resorcinol and an equal quantity of succinic acid or a succinate, moistened with 2 drops of cone. H2SO4. Cool, dissolve in water and add NaOH solution in excess. A red solution is produced which exhibits an intense green fluorescence.-f-... 

Certain salts of divalent metals (e.g., lead and copper formate, calcium acetate) are exceptional in giving bright green fluorescences. In each case confirmatory tests must always be employed. 

Fluorescein reaction. Repeat Test i, using however resorcinol instead of phenol. A reddish solution having an intense green fluorescence is produced. 

Fluorescein reaction. Fuse together in a dry test-tube o-i g. of succinimide, O l g. of resorcinol and 2 drops of cone. HjSOi, Cool, add water and then NaOH solution in excess. A green fluorescent solution is obtained. 

Phthaleins (Phthalic anhydride TH SO.) red green fluorescence usually blue purple red blue- purple — green faint green fluorescence... 

Goelenterate. Coelenterates Penilla reformis (sea pansy) -cradViequoreaforskalea (jelly fish) produce bioluminescence by similar processes (223). The basic luciferin stmcture is (49) (224) and excited amide (50) is the emitter. The stmctural relationship to Varela is evident. A stmctural analogue where R = CH is active ia bioluminescence. The quantum yield is about 4% (223), with at 509 nm (56). This reaction iavolves a charge transfer between green fluorescent proteia and the excited-state coelenterate oxylucifetin. 

In aqueous solution, riboflavin has absorption at ca 220—225, 226, 371, 444 and 475 nm. Neutral aqueous solutions of riboflavin have a greenish yellow color and an intense yellowish green fluorescence with a maximum at ca 530 nm and a quantum yield of = 0.25 at pH 2.6 (10). Fluorescence disappears upon the addition of acid or alkah. The fluorescence is used in quantitative deterrninations. The optical activity of riboflavin in neutral and acid solutions is [a]=+56.5-59.5° (0.5%, dil HCl). In an alkaline solution, it depends upon the concentration, eg, [a] J =—112-122° (50 mg in 2 mL 0.1 Ai alcohohc NaOH diluted to 10 mL with water). Borate-containing solutions are strongly dextrorotatory, because borate complexes with the ribityl side chain of riboflavin = +340° (pH 12). 

Riboflavin can be assayed by chemical, en2ymatic, and microbiological methods. The most commonly used chemical method is fluorometry, which involves the measurement of intense yeUow-green fluorescence with a maximum at 565 nm in neutral aqueous solutions. The fluorometric deterrninations of flavins can be carried out by measuring the intensity of either the natural fluorescence of flavins or the fluorescence of lumiflavin formed by the irradiation of flavin in alkaline solution (68). The later development of a laser—fluorescence technique has extended the limits of detection for riboflavin by two orders of magnitude (69,70). 

Rosenheim reaction CHCI3 + lead tetraacetate in green fluorescence not given by esters of provitamin D can... 

In a 2-1. round-bottom flask, fitted with an efficient reflux condenser, is placed 500 g. (5.7 moles) of ethyl acetate (Note i), and 50 g. (2.2 moles) of clean sodium wire or finely sliced sodium (Note 2) is added. The reaction is at first quite slow, and must be started by warming on a water bath (Note 3). After the reaction is once started it proceeds vigorously and cooling is then necessary in order to avoid loss of material through the condenser. When the rapid reaction slows down, the reaction mixture is heated on a water bath until the sodium has completely dissolved. This usually requires about one and one-half hours. At this stage the reaction mixture should be a clear red liquid with a green fluorescence. 

Purified by recrystn from xylene. Gives yellow-green fluorescent solutions at pH 8.2-9.5, [IR Schnopper et al. Anal Chem 31 1542 7959.] With AcCl naphthol AS-D acetate is obtained m 168-169°, and with... 

Yellow-green fluorescent zones are easily visible against a dark background under long-wavelength UV light (A = 365 run). 

Detection and result The developed chromatogram was freed from mobile phase by drying for 10 min at 110°C, allowed to cool and immersed for 1 s in the reagent solution. The plate was evaluated as rapidly as possible while it was moist since the fluorescent background increased in intensity as the plate dried out. Cholesterol appeared as a yellow-green fluorescent zone hR 20—25). 

Yellow-green fluorescent zones are formed on a dark background in long-wave-length UV light (2 = 365 nm). 

Under long-wavelength UV light (A = 365 nm) the 2-(2-hydroxyphenyl)-benztri-azoles yielded yellow-green fluorescent chromatogram zones, which were, in the cases of Tinuvin P (hRi 20 — 25) and Tinuvin 343 (2-[2-hydroxy-3-(l-methylpropyl)-5-ter/-butylphenyl]benztriazole hR( 45 — 50), suitable for quantitation. 

Glycine (hRf 20 — 25), alanine (hRf 35 — 40), valine (hRf 55 — 60) and leucine (fiRf 65 — 70) appeared as blue-green fluorescent chromatogram zones in long-wave-... 

The glucosides of menthol, citronellol, nerol, geraniol, cw-myrtenol, L-borneol, linalool and a-terpineol yielded yellow-green fluorescent chromatogram zones in long-wavelength UV light (2 = 365 nm). The same applied to arbutin (hRf 45 — 50). 

Green Fluorescent Protein—The Light Fantastic from Jellyfish to Gene Expression... 

Antocatalytic oxidation of GFP amino acids leads to the chromophore shown on the left. The green fluorescence requires fnrtlier interactions of the chromophore witli otlier parts of die protein. 

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