This technical note describes kinetic fluorescence as an analytical technique to quantify non-fluorescent species. The technique is applied to the determination of thiamine (vitamin B1) in solution. Fluorescence intensity is monitored as thiamine converts to fluorescent thiochrome, and a relationship is established between the rate of increase of intensity and the concentration of thiamine. The...

Fluorescence is common in both coral adult and larval stages, and is produced by fluorescent proteins that absorb higher energy light and emit lower energy light. This study investigated the changes of coral fluorescence in different life history stages and the effects of parental light environment on larval fluorescence, larval endosymbiotic dinoflagellate abundance, larval size and settlement...

The overproduction of acidic byproducts is implicated in the development of numerous diseases, and there is currently great interest in developing contrast agents that can image acidic tissue in vivo.1 Here we report a pH-sensing biodegradable near-infrared (NIR) nanoprobe capable of providing complementary information through both fluorescence lifetime measurements and signal amplification in ...

This technical note describes kinetic fluorescence as an analytical technique to quantify non-fluorescent species. The technique is applied to the determination of thiamine (vitamin B1) in solution. Fluorescence intensity is monitored as thiamine converts to fluorescent thiochrome, and a relationship is established between the rate of increase of intensity and the concentration of thiamine. The...

We studied fluorescence intensity, polarization and lifetime of some commonly used fluorophores conjugated to oligodeoxyribonucleotides with different primary and secondary structures. We found that fluorescence intensity can increase or decrease upon hybridization of the labeled strand to its complement depending on the sequence and position of the fluorophore. Up to 10-fold quenching of the f...

Mitochondrial DNA (mtDNA) in tumor cells was found to play an important role in maintaining the malignant phenotype. Using laser scanning confocal fluorescence microscopy (LSCFM) in a recent work, we reported a variable fluorescence intensity of ethidium bromide (EB) in mitochondria nucleoids of living carcinoma cells. Since when EB is bound to nucleic acids its fluorescence is intensified; a h...

The question whether two proteins interact with each other or whether a protein localizes to a certain region of the cell is often addressed with fluorescence microscopy and analysis of a potential colocalization of fluorescence markers. Since a mere visual estimation does not allow quantification of the degree of colocalization, different statistical methods of pixel-intensity correlation are ...

Some new compounds based on bis-benzimidazole moieties have been synthesized and characterized by IR and NMR spectroscopies. The ability of 3a in transition metal cation sensing such as Co2+, Ni2+, Zn2+, Mn2+, Fe2+ and Cu2+ have been investigated by Uv-vis and fluorescence spectroscopy in methanol solvent. The complexation constants and complex stoichiometry of Cu2+ have been determined. The ex...

In this study, highly ordered mesoporous silica material (SBA-15) functionalized with Diethyl 2 - (9 -fluorenyl) malonate as a flourophore is reported. The anchoring of flourophores to the hydroxyl group on SBA-15 surface was done with post synthesis method. The obtained materials were characterized by small and wide angle X-ray diffraction, N2 adsorption–desorption, Fourier transform infrared ...

Optical measurements of metabolism are ideally acquired in vivo; however, intravital measurements are often impractical. Accurate ex vivo assessments would greatly broaden the applicability of optical measurements of metabolism. We investigate the use of live tissue culture experiments to serve as a surrogate for in vivo metabolic measurements. To validate this approach, NADH and FAD fluorescen...