Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Fluorescence Microscopy”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 199 records · Page 11Linked to original sources
PubMed1983

Total internal reflection fluorescent microscopy.

This review discusses applications of fluorescence microscopy using totally internally reflected excitation light. When totally internally reflected in a transparent solid at its interface liquid, the excitation light beam penetrates only a short distance into the liquid. This surface electromagnetic field, called the 'evanescent wave', can selectively excite fluorescent molecules in the liquid near the interface. Total internal reflection fluorescence (TIRF) has been used to examine the cell/substrate contact regions of primary cultured rat myotubes with acetylcholine receptors labelled by fluorescent alpha-bungarotoxin and human skin fibroblasts labelled with a membrane-incorporated fluorescent lipid. TIRF examination of cell/surface contacts dramatically reduces background from cell autofluorescence and debris. TIRF has also been combined with fluorescence photobleaching recovery and correlation spectroscopy to measure the chemical kinetic binding rates and surface diffusion constant of fluorescent labelled serum protein binding (at equilibrium) to a surface.

Animals↗
PubMed2001

Spatial distribution of perylenequinones in lichens and extended quinones in quincyte using confocal fluorescence microscopy.

The application of confocal fluorescence microscopy and microspectrofluorimetry to the characterization of the distribution of organic compounds in bulk lichens and mineral structures is demonstrated. Perylenequinones and extended quinones were chosen as both model compounds and as the naturally occurring fluorophores. These molecules occur, respectively, in corticolous microlichens and in a pink-colored mineral called quincyte. The structures of quincyte and of the lichens Cryptothelium rhodotitton and Graphis hematites are described, and the possibilities of energy dissipation and photoprotection mechanisms in these lichens are discussed. This study also illustrates how, for a wide range of specimens, naturally occurring quinone fluorophores in the specimen can be exploited directly to yield chemical and structural information without using fluorescent labelling. These intrinsic quinonoid compounds have molecular fluorescence yields and laser damage thresholds comparable or superior to common microscopy dyes, and can therefore be used to obtain high-contrast 3D fluorescence imaging without the complications introduced by dye labelling.

Lichens↗
PubMed1998

The value of fluorescence microscopy of auramine stained sputum smears for the diagnosis of pulmonary tuberculosis.

Laboratory diagnosis of pulmonary tuberculosis rests on the bacteriological examination of sputum smears stained by the Ziehl-Neelsen (ZN) method for acid fast bacilli (AFB). In the present study, we have compared light microscopy of ZN stained smears with that of fluorescence microscopy of sputum smears stained by auramine-phenol flurochrome dye for detection of AFB in sputum specimens. Sputum specimens from a total of 2,600 clinically suspected and diagnosed cases of pulmonary tuberculosis were examined by both the methods. Sputum specimens from a total of 1,104 patients were found to be positive for AFB. These included sputa from 975 (37.5%) patients positive for AFB by both ZN and auramine staining methods and sputa from an additional 129 (4.96%) patients positive for AFB by auramine staining only. Thus auramine staining of sputum smears in comparison to that of ZN staining is a better method of sputum microscopy for demonstration of AFB in sputum specimens. Fluorescence microscopy is relatively more sensitive and has the added advantage of allowing a large number of sputum specimens to be examined in a given time, in laboratories equipped with a fluorescent microscope.

Bacteriological Techniques↗
PubMed1991

Confocal fluorescence microscopy in modern cell biology.

Confocal fluorescence microscopy has become a major tool in modern cell biology. The paper explains the basic principles and especially the depth discrimination properties of confocal microscopy. An important application is described briefly and outlined with some figures. The paper concludes with remarks on features to be expected in the near future.

Animals↗
PubMed1985

The screening of more than 2,000 schoolgirls for bacteriuria using an automated fluorescence microscopy system.

After initial evaluation of a manual fluorescence microscopy system on a variety of urines the method was automated and subsequently tested in a population survey of urinary tract infection in schoolgirls. This automated Bactoscan system allowed a rapid analysis of urine samples and with the introduction of modifications to the staining protocol it correctly eliminated 91% of samples as being not significantly infected.

Autoanalysis↗
PubMed2004

Annexin A1 interaction with a zwitterionic phospholipid monolayer: a fluorescence microscopy study.

We present the results of a fluorescence microscopy study of the interaction of annexin A1 with dipalmitoylphosphatidylcholine (DPPC) monolayers as a function of the lipid monolayer phase and the pH of the aqueous subphase. We show that annexin A1-DPPC interaction depends strongly on the domain structure of the DPPC monolayer and only weakly on the subphase pH. Annexin A1 is found to be line active, with preferential adsorption at phase boundaries. Also, annexin A1 is found to form networks in the presence of a domain structure in the monolayer. Our results point toward an important contribution of the unique N-terminal domain to the organization of the protein at the interface.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1978

Improved identification of methanogenic bacteria by fluorescence microscopy.

Methanogenic bacteria can be tentatively identified by fluorescence microscopy. This technique was improved by carefully selecting a series of excitation and barrier filters that matched the excitation and emission spectra of some unique coenzymes viz., F420 and F350, in methanogenic bacteria.

Escherichia coli↗
PubMed2000

Raising the speed limits for 4D fluorescence microscopy.

Three-dimensional time-lapse (4D) fluorescence microscopy is becoming a routine experimental tool. This article summarizes current technologies, and describes a new method for speeding image acquisition during 4D confocal microscopy.

Image Processing, Computer-Assisted↗
PubMed1982

Evaluation of fluorescence microscopy for the identification of necrotic myocardium.

The utility of fluorescence microscopy in the evaluation of hematoxylin-eosin-stained sections for the presence of myocardial necrosis was examined. Sixteen human autopsy cases with clinical and pathologic evidence of myocardial infarction were studied. In addition, to better define the sensitivity and specificity of this technique, the hearts of 20 dogs that had undergone experimental coronary occlusion of known duration were studied; the duration of occlusion was three hours in seven dogs, six hours in seven dogs, and seven days in six dogs. In both human and dog studies, hypereosinophilic necrotic fibers in hematoxylin-eosin-stained sections appeared bright yellow by fluorescence microscopy. In myocardium that was shown to be necrotic by triphenyltetrazolium chloride staining and electron microscopy but was not hypereosinophilic, there was no bright yellow fluorescence of myofibers. Our study shows that bright yellow fluorescence is related to hypereosinophilia of myofibers and thus can be used to detect myocardial necrosis. However, since only hypereosinophilic fibers show the characteristic yellow fluorescence, the method appears to offer no distinct advantages over routine light microscopic techniques.

Animals↗
PubMed2000

Characterization and prevention of phototoxic effects in intravital fluorescence microscopy in the hamster dorsal skinfold model.

Intravital microscopy is widely used to study the microcirculation. However, the use of fluorescent dyes can induce phototoxic effects which may affect the measurements, particularly in tissue exposed to oxidative stress. The aim of the study was to determine the threshold light dose at which fluorescent microscopy is associated with phototoxic effects in the hamster dorsal skinfold chamber under normal and pathological conditions. The extent of phototoxicity in the microcirculation in the hamster skinfold chamber was investigated using intravital fluorescent microscopy during 60 min of illumination (1048 mW/cm2) applying two different concentrations of fluorescein isothiocyanate dextran under baseline conditions (groups A and B) and following 4 h of ischemia (groups C and D). In the second part of the study the microvasculature was analyzed regarding phototoxic effects during a standardized intravital microscopic examination after 4 h of pressure induced ischemia. Groups I and II (n=7) were studied using epiillumination after injection of fluorescein isothiocyanate dextran plus rhodamine 6G or rhodamine 6G only. In group III (n=7) only transillumination was used. Arteriolar vasospasm, microvascular perfusion failure, thrombus formation, and enhanced leukocyte endothelium interaction were observed as signs of a phototoxic effect in normal tissue. However, the light doses needed to induce these effects clearly exceeded those during standard examinations. The induction of a 4-h ischemia and reperfusion further enhanced these effects. Despite the predamage by ischemia/reperfusion the comparison of epiillumination and transillumination microscopy using a standard protocol showed no differences regarding the parameters analyzed at any time. This indicates that epiillumination and the fluorescent dyes per se did not affect the experimental results. These results show that ischemia/reperfusion studies in the dorsal skinfold chamber of the Syrian golden hamster can be carried out safely without the risk of inducing phototoxic effects by fluorescent microscopy. Nevertheless every laboratory using epiillumination and fluorescent dyes should take precautions to avoid these effects by the use of sensitive cameras to lower the light dose.

Animals↗
PubMed2002

To 5D and beyond: quantitative fluorescence microscopy in the postgenomic era.

Digital fluorescence microscopy is now a standard technology for assaying molecular localisation in cells and tissues. The choice of laser scanning (LSM) and wide-field microscopes (WFM) largely depends on the type of sample, with LSMs performing best on thick samples and WFMs performing best on thin ones. These systems are increasingly used to collect large multidimensional datasets. We propose a unified image structure that considers space, time, and fluorescence wavelength as integral parts of the image. Moreover, the application of fluorescence imaging to large-scale screening means that large datasets are now routinely acquired. We propose that analysis of these data requires querying tools based on relational databases and describe one such system.

Animals↗