pH dependent spectral properties of sodium fluorescein ophthalmic solutions revisited

Doughty, Michael J.

doi:10.1111/j.1475-1313.2009.00703.x

Cited by 73 publications

(66 citation statements)

References 17 publications

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“…We therefore, adjusted the buffer to pH 5.44 for improved antioxidant stability. Due to the impact of pH on fluorescein light emissions (Doughty, 2010), for maintained sensitivity, we increased the concentration of fluorescein and AAPH as compared to previously published methods (Cao G, 1993). 75uL of 1.9uM fluorescein in a 75mM sodium acetate buffer (pH 5.44) were added to each well of the plate followed by 50uL of sample: diluted tea (0.09g/L), Trolox control (50uM) or buffer as a blank.…”

Section: Methodsmentioning

confidence: 99%

Effects of brewing conditions on the antioxidant capacity of twenty-four commercial green tea varieties

et al. 2016

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A novel paper-based Nanoceria Reducing Antioxidant Capacity (NanoCerac) assay for antioxidant detection (Sharpe, Frasco, Andreescu, & Andreescu, 2012), has been adapted for the first time as a high-throughput method, in order to measure the effect of brewing conditions and re-infusion on the antioxidant capacity of twenty-four commercial green teas. The oxygen radical absorbance capacity (ORAC) assay, frequently applied to complex foods and beverages, was used as a comparator measure of antioxidant capacity. A novel measure of sustained antioxidant capacity, the total inherent antioxidant capacity (TI-NanoCerac and TI-ORAC) was measured by infusing each tea six times. Effects of brewing conditions (temperature, brew time, etc.) were assessed using one popular tea as a standard. Both NanoCerac and ORAC assays correlated moderately (R2 0.80 ± 0.19). The average first-brew NanoCerac, TI-NanoCerac, first-brew ORAC and TI-ORAC were: 0.73 ± 0.1 GAE/g tea ; 2.4 ± 0.70 mmol GAE/g tea; 1.0 ± 0.3 mmol TE/g tea and 2.1 ± 0.71 mmol TE/g tea respectively. Brewing conditions including water temperature and infusion time significantly affected antioxidant capacity. The high-throughput adaptation of the original NanoCerac assay tested here offered advantages over ORAC, including portability and rapid analysis.

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Section: Methodsmentioning

confidence: 99%

Effects of brewing conditions on the antioxidant capacity of twenty-four commercial green tea varieties

et al. 2016

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“…In fact, control measurements with fluorescein revealed comparable dependences of the fluorescence maximum intensity and position as in the APF experiments. Both effects can be explained by aggregation of fluorescein (47)(48)(49). Moreover, fluorescein shows pH-dependent fluorescence properties due to changes in the ratio of the mono-and dianionic form (50,51).…”

Section: Discussionmentioning

confidence: 99%

The Fluorescein-derived Dye Aminophenyl Fluorescein Is a Suitable Tool to Detect Hypobromous Acid (HOBr)-producing Activity in Eosinophils

Flemmig

Zschaler

Remmler

et al. 2012

Journal of Biological Chemistry

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Background: Aminophenyl fluorescein was developed to detect the halogenating activity of myeloperoxidase. Results: Aminophenyl fluorescein can also be used to quantify the formation of HOBr by eosinophil peroxidase. Conclusion: Aminophenyl fluorescein is suitable to evaluate the halogenating activity of eosinophil peroxidase and peroxidase activity modulators. Significance: Eosinophil peroxidase, a mammal heme peroxidases family member, may contribute to the regulation of inflammation.

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“…Fluorescein bound to intracellular proteins, including albumin, could reveal fluorescence quenching, both static and dynamic. In addition, Doughty 21 reported that the fluorescence of sodium fluorescein was clearly influenced by both pH and concentration. Both the absorption and resultant fluorescence declined as the pH is reduced from 8.5 to lower pH values.…”

Section: Discussionmentioning

confidence: 99%

Monocarboxylate Transporters Mediate Fluorescein Uptake in Corneal Epithelial Cells

Sun

Liou

Yeh

et al. 2017

Invest. Ophthalmol. Vis. Sci.

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PURPOSE.To determine the presence of monocarboxylate transporter (MCT) in human and rabbit corneal epithelium and its role in transcellular fluorescein transportation in the cornea. METHODS.The presence of MCTs in human and rabbit corneal epithelium was determined by RT-PCR and immunohistochemistry. Intracellular fluorescein uptake experiment was performed using cultured human corneal epithelial cells (HCECs). The involvement of MCT in fluorescein uptake was determined by addition of MCT inhibitors to HCECs and acute dry eye model on New Zealand albino rabbits by spectrophotometry, corneal impression cytology, and external eye photographs. RESULTS.MCT-1 and MCT-4 were identified in both human and rabbit corneal epithelia. A longer treatment period and a lower pH value in culture medium increased fluorescein uptake in HCECs. Fluorescein uptake in HCECs was decreased following addition of MCT inhibitors in a concentration-dependent manner. Impression cytology under fluorescent microscopy showed intracellular fluorescein staining in the rabbit cornea with acute dry eye treatment that was decreased following topical treatment of MCT inhibitors. CONCLUSIONS. Fluorescein ingress in corneal epithelial cells is mediated by the MCT family.Further study of MCT-mediated transport on HCECs may potentially benefit differential diagnosis and contribute better understandings of ocular surface disorders.

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pH dependent spectral properties of sodium fluorescein ophthalmic solutions revisited

Abstract: The present studies confirm and extend some earlier reports that pH (over the range of 4.0-8.5), as well as concentration, predictably determines the fluorescence emission of dilute aqueous solutions of NaF.

Cited by 73 publications

References 17 publications

Effects of brewing conditions on the antioxidant capacity of twenty-four commercial green tea varieties

Effects of brewing conditions on the antioxidant capacity of twenty-four commercial green tea varieties

The Fluorescein-derived Dye Aminophenyl Fluorescein Is a Suitable Tool to Detect Hypobromous Acid (HOBr)-producing Activity in Eosinophils

Monocarboxylate Transporters Mediate Fluorescein Uptake in Corneal Epithelial Cells

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