Using the hamster cheek pouch carcinogenesis model, we explore which fluorescence excitation wavelengths are useful for the detection of neoplasia. 42 hamsters were treated with DMBA to induce carcinogenesis, and 20 control animals were treated only with mineral oil. Fluorescence excitation emission matrices were measured from the cheek pouches of the hamsters weekly. Results showed increased f...

.a simple spectrofluorimetric method is described for the determination of doxorubicin (dxr) based on its quenching effect on the fluorescence intensity of tb 3+ - deferasirox (dfx) complex as a fluorescent probe. the excitation and emission wavelengths were 328 and 545 nm, respectively. the effects of ph, time, order of addition of reagents, concentrations of tb 3+ and dfx and the buffer volum...

Laser-induced autofluorescence measurement of the brain was performed to assess its spectroscopic properties and to distinguish brain tumors from the normal tissues. The excitation-induced emission spectra were plotted on a 2-dimensional map, the excitation-emission matrix, to determine the excitation wavelengths most sensitive for the spectroscopic identification of brain tumors. The excitatio...

Second order advantage of excitation-emission fluorescence matrix was applied for the simultaneous determination of ibuprofen and caffeine. The proposed method is based on the measurement of the native fluorescence and recording emission spectra of ibuprofen and caffeine in different excitation wavelengths. The mixture of these compounds was resolved by multivariate curve resolution coupled wit...

AIM To investigate the autofluorescence spectroscopic differences in normal and adenomatous colonic tissues and to determine the optimal excitation wavelengths for subsequent study and clinical application. METHODS Normal and adenomatous colonic tissues were obtained from patients during surgery. A FL/FS920 combined TCSPC spectrofluorimeter and a lifetime spectrometer system were used for flu...

Fluorescence microscopy with an improved contrast for fluorescence images is developed using an optical interference mirror (OIM) slide, which can enhance the fluorescence from a fluorophore as a result of the double interference of the excitation light and emission light. To improve the contrast of a fluorescence image using an OIM slide, a linearly-polarized excitation light was employed, and...

We isolated and characterized a green fluorescent protein (GFP) from the sea cactus Cavernularia obesa. This GFP exists as a dimer and has absorption maxima at 388 and 498 nm. Excitation at 388 nm leads to blue fluorescence (456 nm maximum) at pH 5 and below, and green fluorescence (507 nm maximum) at pH 7 and above, and the GFP is remarkably stable at pH 4. Excitation at 498 nm leads to green ...

Many naturally occurring substances are intrinsically fluorescent (autofluorescent) when excited with UV or visible wavelengths. Autofluorescence emission typically spans the visible spectrum with a lifetime (?) measured in nanoseconds. Time-resolved fluorescence techniques exploit the large difference in ? that exists between typical autofluorophores and for example, lanthanide chelates (typic...

Based on a fluorescence imaging model, the optical filters, such as excitation and emission filters, are determined by linear discriminant analysis. The discriminability is a quadratic Rayleigh quotient of one filter if the other filter is assumed to be constant. The optical filters are optimized alternatingly and iteratively by solving their generalized eigenvalue problems. The proposed method...

a validated hplc method was developed to determine doxorubicin concentration in a small volume of rat plasma (60 µl) with convenient fluorescence detection. sample preparation includes a simple one-step liquid-liquid extraction using minimum amount of organic solvent, with extraction recoveries more than 95%. the analysis was accomplished using perfectsil c18 column maintained at 35 °c and a mo...