Application Of Fluorescent Dyes Research Articles

Tailored Supramolecular Cage for Efficient Bio-Labeling.

Fluorescent chemosensors are powerful imaging tools used in a broad range of biomedical fields. However, the application of fluorescent dyes in bioimaging still remains challenging, with small Stokes shifts, interfering signals, background noise, and self-quenching on current microscope configurations. In this work, we reported a supramolecular cage (CA) by coordination-driven self-assembly of benzothiadiazole derivatives and Eu(OTf)3. The CA exhibited high fluorescence with a quantum yield (QY) of 38.57%, good photoluminescence (PL) stability, and a large Stokes shift (153 nm). Furthermore, the CCK-8 assay against U87 glioblastoma cells verified the low cytotoxicity of CA. We revealed that the designed probes could be used as U87 cells targeting bioimaging.

Investigating Mitochondrial Ca2+ Dynamics in Isolated Mitochondria and Intact Cells: Application of Fluorescent Dyes and Genetic Reporters.

Mitochondrial Ca2+ buffering is a hallmark of eukaryotic cellular physiology, contributing to the spatiotemporal shaping of the cytosolic Ca2+ signals and regulation of mitochondrial bioenergetics. Often, this process is altered in a pathological context; therefore, it can be scrutinized experimentally for therapeutic intervention. In this chapter, we describe fluorescence and bioluminescence measurement of mitochondrial Ca2+ in both isolated mitochondria and intact cells.

A fresh look at mycobacterial pathogenicity with the zebrafish host model.

The zebrafish has earned its place among animal models to study tuberculosis and other infections caused by pathogenic mycobacteria. This model host is especially useful to study the role of granulomas, the inflammatory lesions characteristic of mycobacterial disease. The optically transparent zebrafish larvae provide a window on the initial stages of granuloma development in the context of innate immunity. Application of fluorescent dyes and transgenic markers enabled real‐time visualization of how innate immune mechanisms, such as autophagy and inflammasomes, are activated in infected macrophages and how propagating calcium signals drive communication between macrophages during granuloma formation. A combination of imaging, genetic, and chemical approaches has revealed that the interplay between macrophages and mycobacteria is the main driver of tissue dissemination and granuloma development, while neutrophils have a protective function in early granulomas. Different chemokine signaling axes, conserved between humans and zebrafish, have been shown to recruit macrophages permissive to mycobacterial growth, control their microbicidal capacity, drive their spreading and aggregation, and mediate granuloma vascularization. Finally, zebrafish larvae are now exploited to explore cell death processes, emerging as crucial factors in granuloma expansion. In this review, we discuss recent advances in the understanding of mycobacterial pathogenesis contributed by zebrafish models.

Engineering Bacterial Shape Using Soft Matter Microchambers.

This article describes the design and fabrication of microchambers that are used for the study of bacterial cells. The design allows for the confinement and precise manipulation of bacterial cell shape. The application of fluorescent dyes and fluorescent proteins enables the precise analysis of the localization of biomolecules within confined bacterial cell. This article also outlines three methods to engineer cell shape from a filamentous cell type and from spheroplasts without a cell wall using soft lithography-based technologies. © 2018 by John Wiley & Sons, Inc.

Застосування флуоресцентних барвників для оцінки стану деконсервованих еритроцитів коня і бика

Застосування флуоресцентних барвників для оцінки стану деконсервованих еритроцитів коня і бика

CARS based label‐free assay for assessment of drugs by monitoring lipid droplets in tumour cells

Coherent anti-Stokes Raman scattering (CARS) is becoming an established tool for label-free multi-photon imaging based on molecule specific vibrations in the sample. The technique has proven to be particularly useful for imaging lipids, which are abundant in cells and tissues, including cytoplasmic lipid droplets (LD), which are recognized as dynamic organelles involved in many cellular functions. The increase in the number of lipid droplets in cells undergoing cell proliferation is a common feature in many neoplastic processes [1] and an increase in LD number also appears to be an early marker of drug-induced cell stress and subsequent apoptosis [3]. In this paper, a CARS-based label-free method is presented to monitor the increase in LD content in HCT116 colon tumour cells treated with the chemotherapeutic drugs Etoposide, Camptothecin and the protein kinase inhibitor Staurosporine. Using CARS, LDs can easily be distinguished from other cell components without the application of fluorescent dyes and provides a label-free non-invasive drug screening assay that could be used not only with cells and tissues ex vivo but potentially also in vivo.

A simple, rapid method to isolate salt glands for three-dimensional visualization, fluorescence imaging and cytological studies

BackgroundSome plants inhabiting saline environment remove salts via the salt glands embedded in the epidermal tissues. Cytological studies of salt glands will provide valuable information to our understanding of the secretory process. Previous studies on salt gland histology relied mainly on two-dimensional microscopic observations of microtome sections. Optical sectioning properties of confocal laser scanning microscope offer alternative approach for obtaining three-dimensional structural information of salt glands. Difficulty in light penetration through intact leaves and interference from neighbouring leaf cells, however, impede the acquiring of good optical salt gland sections and limit its applications in salt gland imaging. Freeing the glands from adjacent leaf tissues will allow better manipulations for three-dimensional imaging through confocal laser scanning microscopy.ResultsHere, we present a simple and fast method for the isolation of individual salt glands released from the interference of neighbouring cells. About 100-200 salt glands could be isolated from just one cm2 of Avicennia officinalis leaf within hours and microscopic visualization of isolated salt glands was made possible within a day. Using these isolated glands, confocal laser scanning microscopic techniques could be applied and better resolution salt gland images could be achieved. By making use of their intrinsic fluorescent properties, optical sections of the gland cells could be acquired without the use of fluorescent probes and the corresponding three-dimensional images constructed. Useful cytological information of the salt gland cells could also be obtained through the applications of fluorescent dyes (e.g., LysoTracker® Red, FM®4-64, Texas Red®).ConclusionsThe study of salt glands directly at the glandular level are made possible with the successful isolation of these specialized structures. Preparation of materials for subsequent microscopic observations of salt glands could be achieved within a day. Potential applications of confocal fluorescence microscopic techniques could also be performed using these isolated glands. Experiments designed and targeted directly at the salt glands were explored and cytological information obtained herein could be further incorporated towards the understanding of the mechanism underlying secretion in plant salt glands.

Chemische und spektroskopische Aspekte der Verwendung von Farbstoffen in der vitreoretinalen Chirurgie

The advantages of the use of optical contrast agents in surgery, such as vitreoretinal microsurgery, are presented. Requirements concerning these materials and the potentials and limitations of their application are discussed on the basis of their coloristic properties. Applications of fluorescent dyes are examined.

Recovery and quantification of bacterial cells associated with streambed sediments

Efficient detachment and purification of bacterial cells associated with streambed sediments are required in order to quantify cell abundance and to assess community composition through the application of epifluorescence microscopy techniques. We applied chemical (i.e., sodium pyrophosphate and polysorbate) and physical treatments (i.e., shaking and sonication), followed by Nycodenz density gradient centrifugation to efficiently recover benthic bacteria. This procedure resulted in a highly purified cell suspension allowing for a precise cell quantification through the application of fluorescent dyes. About 93% of total cells were recovered from the original sediment, with higher recovery from the finer grain-size class (90%) in comparison to the coarse fraction (69%). The potential damaging effects of the applied procedures on cell integrity were assessed on planktonic bacteria in a pre-filtered water control. As a consequence of the high purity of the extracted bacteria, flow cytometry was successfully applied as counting method for sediment cell suspension. However, a significant decrease of protein synthesis in purified samples was measured by estimating the 3H-Leucine incorporation rates, rising uncertainties on the possibility to apply potential metabolic assays after Nycodenz purification.

Diagnostic laparoscopy.

Diagnostic laparoscopy is increasingly being used to aid decision-making in the treatment of serious diseases. The majority of papers on the topic published during the last year have been concerned with preoperative assessment of malignant diseases of the gastrointestinal tract, and have shown that laparoscopy alone--or, even better, in combination with laparoscopic ultrasonography--is able to identify metastatic disease and therefore to reduce significantly the risk of unnecessary laparotomies. New techniques such as the application of fluorescent dyes may improve these results even further. Surgeons are increasingly using diagnostic laparoscopy in patients with acute abdomen and abdominal trauma--a minimally invasive strategy that should also be supported by gastroenterologists. Close cooperation between surgeons and gastroenterologists can also be promoted by using laparoscopy in critically ill patients in intensive-care units when a decision needs to be taken on whether or not laparotomy should be performed. The technique of diagnostic laparoscopy is returning to widespread use after a period of decline.

Macropore flow on a reclaimed surface mine: infiltration and hillslope hydrology

Surface coal mining in central Pennsylvania alters the physical and hydrological properties of soil from its undisturbed state and changes the surface hydrologic response to precipitation. Newly reclaimed minesoils exhibit low, steady-state rates of infiltration (1–2 cm/h) and produce runoff dominated by infiltration-excess overland flow. Within 4 years after reclamation, rates of infiltration on some minesoil surfaces approach pre-mined rates (8 cm/h). As a greater percentage of rainfall infiltrates these reclaimed minesoils, little change occurs in the total volume of surface storm runoff on an event basis. This indicates that infiltrated water contributes to storm runoff by the processes of throughflow and return flow. As the rate of infiltration increases with time, the hydrologic response of the minesoil is controlled by rapid macropore throughflow within the unsaturated minesoil. Application of fluorescent dyes on the reclaimed surface reveals preferred flowpaths through macropores surrounding the numerous, large rock fragments in the minesoil. Development and integration of a macropore network on a reclaimed, surface-mined watershed has a significant, direct effect on the contributions to surface storm runoff from infiltration-excess overland flow, throughflow, and return flow. As rates of infiltration increase through time and slightly delayed macropore return flow increases, the peak rate of surface storm runoff is reduced, therefore reducing the potential for severe gully erosion on the reclaimed site. In addition, throughflow moves predominantly within the minesoil horizon and has limited contact with potentially acid-producing backfill. Better understanding of the process of macropore flow in reclaimed minesoils will help investigators evaluate past strategies and develop new reclamation techniques that will optimize the long-term effluent and ground water quality while minimizing the short-term surface erosional effects of mining and reclamation.

ChemInform Abstract: Synthesis and Application of Fluorescent Dyes on Basis of 1,8‐ Naphthalic Carboximides.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Synthesis and application of Fluorescent Dyes on basis of 1,8-naphthalic carboximides

The naphthalimide derivatives (2a–g, 3a–e) were synthesized from 1,8-naphthalic carboximides. They show green fluorescence, and are suitable for dyenig of textile materials and epoxy resins. The colour parameters of the dyed fabrics were measured. The assessment of colour was made in terms of CIE tristimulus values as well as the position of colour in CIELAB coordinates (L*, a*, b*). The correlation between colour and structure of the dyes is discussed.