This study assesses one possible cause of inter-patient variation in fluorescence spectroscopy of the cervix: the menstrual cycle. Ten patients with no history of an abnormal Pap smear were seen daily throughout 30 consecutive days of their cycle. Fluorescence excitation-emission matrices were measured from three cervical sites on each patient. Principal component analysis was used to determine...

Confocal fluorescence correlation spectroscopy as a time-averaging fluctuation analysis combining maximum sensitivity with high statistical confidence has proved to be a very versatile and powerful tool for detection and temporal investigation of biomolecules at ultralow concentrations on surfaces, in solutions, and in living cells. To probe the interaction of different molecular species for a ...

A new lead fluoroborate glass (PbO-PbF2-B2O3) doped with ytterbium (Yb:PbFB) is presented. Samples with different concentrations of Yb3+ were produced and had their emission cross-sections, fluorescence lifetimes and minimum pump intensities determined. They have high refractive index of 2.2 and a density of 4.4 g/cm3. For a doping level of 1.153x1020 ions/cm3, the fluorescence lifetime, after ...

DNA oligomers can stabilize few-atom Ag clusters in aqueous solution. Some of the resulting AgDNAs are fluorescent with chemical stabilities, excitation and emission wavelengths, and quantum yields that depend strongly on the DNA sequence. 6 This sequence dependence has been exploited for detecting disease-related DNA mutations and for identifying promising biolabels. Rational design of AgDNA f...

The effects of the nonlinear behavior of fluorescent intensity with excitation intensity on emission reabsorption laser-induced fluorescence (ERLIF) are investigated. Excitation nonlinearities arise mainly as a consequence of the depletion of the ground-state population stemming from the finite lifetime of molecules in the excited state. These nonlinearities hinder proper suppression of the exc...

Fluorescence spectroscopy was examined as a potential technique for identification and classification of bacterial pathogens. Colonies of Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella typhi, and Klebsiella pneumoniae on agar plates were measured directly using a laboratory spectrofluorimeter coupled with optical fiber. Steady state fluorescence spectra were collected following excit...

We report on the discovery, isolation, and use of a novel yellow fluorescent protein. Lucigen Yellow (LucY) binds one FAD molecule within its core, thus shielding it from water and maintaining its structure so that fluorescence is 10-fold higher than freely soluble FAD. LucY displays excitation and emission spectra characteristic of FAD, with 3 excitation peaks at 276 nm, 377 nm, and 460 nm and...

Wavelength-selective fluorescence comprises a set of approaches based on the red edge effect in fluorescence spectroscopy, which can be used to monitor directly the environment and dynamics around a fluorophore in a complex biological system. A shift in the wavelength of maximum fluorescence emission toward higher wavelengths, caused by a shift in the excitation wavelength toward the red edge o...

a rapid and sensitive hplc method has been developed for the quantification of mirtazapine (mrz), a noradrenergic and specific serotonergic inhibitor antidepressant (nassa) and its two major metabolites n-desmethylmirtazapine (ndm) and 8-hydroxymirtazapine (8-ohm) in human plasma. the separation was achieved using chromolith c18 column and a mobile phase of acetonitrile: phosphate buffer (ph=3,...

Spectrofluorometric imaging microscopy is demonstrated in a confocal microscope using a supercontinuum laser as an excitation source and a custom-built prism spectrometer for detection. This microscope system provides confocal imaging with spectrally resolved fluorescence excitation and detection from 450 to 700 nm. The supercontinuum laser provides a broad spectrum light source and is coupled ...