Pyranine fluorescence

Soybean (Glycine max Merr. cv Kent) mechanical agitation in the presence of PGA elicitor pyranine fluorescence [178]... 

Tomato (Lycopersicon esculentum) pressiue (50 mPa) pyranine fluorescence [181]... 

Soybean (Glycine max) direct apphcation of pressure to slide-moimted cells osmotic stress pyranine fluorescence 2, 7 -dichlorofluorescein diacetate [183]... 

Use of the pH-sensitive membrane-impermeable flurophore pyranine based on the ratiometric method, which determines directly level of dissociation of pyranine from the ratio between the charged (nnprotonated) pyranine and total pyranine in the intraliposome aqneons phase Addition of impermeable DPX, which acts as a quencher to pyranine fluorescence, into the liposome external medium ensures lack of contribution of extraliposome medium pyranine fluorescence (18,22). This method is considered invasive as the pyranine has to be added in the hydration medium prior to liposome preparation and cannot be used for pH determination of intraliposome aqueous phase... 

Flora, K. K. Dabrowski, M. A. Musson, S. P. Brennan, J. D., The effect of preparation and aging conditions on the internal environment of sol-gel derived materials as probed by 7-azaindole and pyranine fluorescence. Canadian Journal of Chemistry 1999, 77(10), 1617-1625... 

Ziegler, M. Penefsky, H. S. The adenine nucleotide translocase modulates oligomycin-induced quenching of pyranine fluorescence in submitochondrial particles. J. Biol. Chem. 1993, 268, 25320-25328. 

Tri-Na salt [6358-69-6]. C.L Solvent green 7. Pyranine Fluorescent dye. Yellow needles (-1- H O). 

Some fluorescent dyes are more stable than others. For example, our experience suggests that Pyranine 1OG is sufficiently stable if samples can be collected within less than 30 min. For wind tunnel measurements of spray drift, success has been obtained with Green S. ... 

Photo-induced proton transfer Aerosol-OT. The efficiency of proton transfer depends on HzO. Pyranine used as a fluorescent probe. Bardez et al., 1984... 

Fig. B4.3.2. Fluorescence decay curves for pyranine in various aqueous environments. See text for the meaning of A, B, C and D (reproduced with permission from Gutman et al.b ).

Fig. 4.11. pH dependence of emission spectra of pyranine in very acidic media. The residual fluorescence of the acidic form at pH > 3 is due to geminate recombination. 

Various pH sensors have been built with a fluorescent pH indicator (fluorescein, eosin Y, pyranine, 4-methylumbelliferone, SNARF, carboxy-SNAFL) immobilized at the tip of an optical fiber. The response of a pH sensor corresponds to the titration curve of the indicator, which has a sigmoidal shape with an inflection point for pH = pK , but it should be emphasized that the effective pKa value can be strongly influenced by the physical and chemical properties of the matrix in which the indicator is entrapped (or of the surface on which it is immobilized) without forgetting the dependence on temperature and ionic strength. In solution, the dynamic range is restricted to approximately two pH units, whereas it can be significantly extended (up to four units) when the indicator is immobilized in a microhetero-geneous microenvironment (e.g. a sol-gel matrix). 

We foimd that the ratiometric method is superior because it is not dependent on pyranine concentration and therefore free of error in pipeting (18,22,54). Calibration curves were constructed by preparing liposomes in which the hydration of the lipids to form MLV was done using solutions of high concentration at the desired pH in the range of 3.0 to 10.0. Gel-exclusion chromatography on a Sephadex column, as mentioned above, yielded a series of liposome preparations with a fixed external pH (pH 7.5), but different internal pH values determined by the buffer used for lipid hydration. Neither KI nor DPX, which quench the fluorescence of aqueous solutions of pyranine, has much effect on the fluorescence intensity of pyranine in the void volume after gel-exclusion chromatography, which indicates the complete removal of the pyranine from the extraliposomal medium. 

In the ratiometric method, the fluorescence intensity of the liposomes containing pyranine (F) and in the presence of the quencher DPX was determined at 520 nm upon excitation at two wavelengths 460 nm (of the charged unprotonated pyranine) and 415 nm (of the pH-independent isosbestic wavelength that describe the total pyranine concentration). The ratio of is described as F. The ratiometric measurement is used to determine the intraliposome aqueous phase pH (18,22). Then nigericin (or nonactine) at final concentration of 5pM was added to disrupt the pH and/or ammonium ion gradient that induce complete gradient collapse and the measurement at the above two excitations was repeated, and indeed it demonstrated a shift of the intraliposome aqueous pH to be identical to the extraliposome medium pH (10). 

Pyranine, 8-hydroxypyrene-l,3,6-trisulfonic acid 8-Hydroxypyrene-1,3,6-trisulfonic acid (HPTS, also known as pyranine) can be used as a pH indicator. At low pH, HPTS fluorescence is greater with 405 nm excitation, whereas at neutral pH, fluorescence at 440 nm excitation is greater than at 405 nm excitation. Therefore, a strong fluorescence signal at 405 nm excitation indicates HPTS in acidic compartments (endosomes and lysosomes) a strong signal at 440 nm indicates HPTS in neutral compartments (cytosol) (126 128). 

The ionophores have been incorporated into the vesicle membranes and cation flux was assessed either by monitoring the fluorescence of pyranine dye encapsulated within vesicles for estimating the proton transport rate or by analyzing the line shape of Na nucleus by NMR spectroscopy to evaluate the flux rate of Na+ 106-110 Qf ionophores were expressed by percent activity relative... 

Chromophoric change. UV/vis- or fluorescent-active and water-soluble chromophores such as pyranine and carboxyfluorescein are encapsulated in... 

Morphological consequences of the photopolymerization of vesicles prepared from (C18H37)2N+(CH3)CH2C6H4-p-CH=CH2Cl were investigated by using pyranine [100], It was seen to bind appreciably to the surface of the vesicle. Changes in the relative intensities of neutral and anionic form fluorescence were... 

Fig. 8 Phase and fluorescence micrographs of membranous vesicular structures formed from a Murchison meteorite extract (left) compared to vesicles formed by a 20 mM de-canoic acid-decanol mixture [72] (center) and a vesicular structure produced by the photoproduct of an interstellar-ice analog [31]. The vesicles produced by the photochemical ice analog product were allowed to capture pyranine, a fluorescent anionic dye, to demonstrate that a true membrane was present. Scale bars show 20, 10, and 5 pm, from left to right...

Fluorescence microphotolysis can be used to measure diffusion in single cellsand nuclear envelope permeability. Pyranine probes have been used to measure internal pH changes in Escherichia coli membrane vesicles. Probe measurements of intralysosomal pH in living cells and perturbation of pH has been described by Ohkuma and Poole.Fluorescence polarization of six membrane probes in embryonal carcinoma cells have been measured by a cell sorter,Fluorescence of pancreatic islets labelled with fluorescein diacetate has been used to show the effects of cations, ionophores, and hypoglycaemic sulphonylureas. ... 

Figure 5. Time-resolved fluorescence of pyranine at the wavelength of maximum

If pK is less than - 2, the acid is very strong in the excited state and, in general, ki is much larger than the reciprocal of the excited-state lifetime, so that the fluorescence of the acidic form is not observed at pH > pK + 2 but only for lower pH values (Figure 4.10B). Eqs (4.55) and (4.56) expressing the pH dependence of Iha and Ia account for the shape of the curves. However, this is not strictly valid when geminate recombination occurs. A weak emission of the acidic form can then be observed. This is the case for pyranine (pK = 7.7, pK = 1.3) (Figure 4.11). 

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