Search results for "Fluorescence microscope"
showing 10 items of 117 documents
Highly Fluorescent and Water-Soluble Diketopyrrolopyrrole Dyes for Bioconjugation
2015
International audience; The preparation of highly water-soluble and strongly fluorescent diketopyrrolopyrrole (DPP) dyes using an unusual taurine-like sulfonated linker has been achieved. Exchanging a phenyl for a thienyl substituent shifts the emission wavelength to near λ=600 nm. The free carboxylic acid group present in these new derivatives was readily activated and the dyes were subsequently covalently linked to a model protein (bovine serum albumin; BSA). The bioconjugates were characterized by electronic absorption, fluorescence spectroscopy and MALDI-TOF mass spectrometry, thus enabling precise determination of the labeling density (ratio DPP/BSA about 3 to 8). Outstanding values of…
Inulin-Ethylenediamine Coated SPIONs Magnetoplexes: A Promising Tool for Improving siRNA Delivery.
2015
An inulin based polycation (Inu-EDA) has been synthesized by the grafting of ethylenediamine molecules onto inulin backbone. The obtained inulin copolymer has been though to coat SPIONs (IC-SPIONs) and obtain stable magnetoplexes by complexation of IC-SPIONs with a model duplexed siRNA, for improving oligonucleotide transfection efficiency.The physical-chemical characteristics of IC-SPIONs and IC-SPIONs/siRNA magnetoplexes have been investigated by scanning and transmission electron microscopies, dynamic light scattering, FT-IR and qualitative surface elementary analysis. Cell compatibility and internalization in vitro of IC-SPIONs have been evaluated by MTS and fluorescence microscopy resp…
Confocal microscopy of single molecules of the green fluorescent protein
1998
Single molecule detection has been extended into life sciences by use of strongly fluorescent labels. The green fluorescent protein (GFP) as a self-fluorescent biomolecule has attracted considerable attention. Here, single molecules of the GFP-mutant Glu222Gln are immobilized in a polyvinylalcohol matrix and detected by confocal fluorescence microscopy. Although this mutant stabilizes one of both conformers of the wild-type GFP, the investigation of its fluorescence dynamics reveals strong signal fluctuations. This fluorescence behaviour is—at least partly—caused by reversible photochemical changes of the protein framework, that can relax into the fluorescent state on different timescales. …
In vivo molecular and morphological imaging by real time confocal mini-microscopy
2006
We evaluated a newly developed miniaturized confocal laser microscopy probe for real-time in vivo molecular and morphological imaging of normal, inflammatory, and malignant tissue in rodents. In the rigid mini-microscopy probe (diameter 7 mm), a single line laser delivers an excitation wavelength of 488 nm. Optical slice thickness is 7 μm, lateral resolution 0.7 μm. The range of the z-axis is 0 - 250 μm below the tissue surface. Organ systems were examined in vivo in rodent models of human diseases. FITC-labeled Lycopersion esculentum lectin was injected or selected cell populations stained for molecular targeting. Morphological imaging was performed using fluorescein sodium, FITC-labeled d…
Inorganic Nanoparticle as a Carrier for Hepatitis B Viral Capsids
2011
Virus like particles (VLP) are used to transport immune response-modulating agents to target cells to treat them. In order to deliver a high concentration of VLP to the cell, a number of VLP can be attached to a nanoparticle to be used as a nanolorry. In this study, SiO2 nanoparticles were attached to Hepatitis B VLP. Spectrophotometry measurements, electron, and fluorescent microscopy evidence showed that the SiO2 – Hepatitis B VLP complexes were formed.
Halloysite nanotubes-carbon dots hybrids multifunctional nanocarrier with positive cell target ability as a potential non-viral vector for oral gene …
2019
Abstract Hypothesis The use of non-viral vectors for gene therapy is hindered by their lower transfection efficiency and their lacking of self-track ability. Experiments This study aims to investigate the biological properties of halloysite nanotubes-carbon dots hybrid and its potential use as non-viral vector for oral gene therapy. The morphology and the chemical composition of the halloysite hybrid were investigated by means of high angle annular dark field scanning TEM and electron energy loss spectroscopy techniques, respectively. The cytotoxicity and the antioxidant activity were investigated by standard methods (MTS, DPPH and H2O2, respectively) using human cervical cancer HeLa cells …
Citocentrifugación como un método adicional para estudiar celomitos de equinodermos: un enfoque comparativo que combina células vivas, preparaciones …
2021
Abstract Introduction: Echinoderm coelomocytes have traditionally been investigated through a morphological approach using light microscopy, which relies on the idea of constant cell shape as a stable character. However, this can be affected by biotic or abiotic conditions. Objective: To analyze if the consistency in cell morphology offered by the cytocentrifugation method, might be used as a convenient tool to study echinoderm coelomocytes. Methods: Cells of Echinaster (Othilia) brasiliensis (Asteroidea), Holothuria (Holothuria) tubulosa (Holothuroidea), Eucidaris tribuloides, Arbacia lixula, Lytechinus variegatus, and Echinometra lucunter (Echinoidea) were spread on microscope slides by c…
Examination Technique of Confocal Laser Endomicroscopy
2007
The first publication about a confocal fluorescence microscope integrated into the distal tip of a conventional colonoscope (Pentax EC 3830FK, Tokyo, Japan) appeared in 2004 [1], showing that in vivo microscopy at subcellular resolution (0.7 µm) simultaneously displayed with white-light endoscopy had become possible. Today, endomicroscopy can be performed in the upper and lower GI tract [2]–[10]. This chapter deals with the examination technique of confocal laser endomicroscopy.
Imaging and force transduction in correlative scanning force and confocal fluorescence microscopy
2018
Correlative scanning force and confocal fluorescence microscopy has been used to study individual molecules, nanoparticles and nanoparticle oligomers. By applying a compressive force via the AFM cantilever, spectral blue and red shifts in the range of several meV/GPa have been observed for single dye molecules and semiconductor quantum dots. Moreover, individual Au nanoparticle dimers linked by a chlorophyll binding protein have been imaged in both modes and plasmonic fluorescence enhancement of the chlorophyll emission of up to a factor of 15 has been found.
Electronic Excitation Energy Transfer in Multichromophoric Assemblies: A Single Molecule Insight
2009
In recent years, single molecule spectroscopy has provided novel insights into the fundamentals of electronic excitation energy transfer in molecular aggregates. In order of increasing structural complexity, we have studied simple molecular dimers and multichromophoric dendrimers. It will be shown that the combination of frequency-selective single molecule spectroscopy and confocal fluorescence microscopy at 1.4 K is a unique tool to study energy transfer processes in these systems. In particular, from the line widths of single molecule excitation spectra, rate constants of energy transfer can be deduced directly. A detailed analysis shows that, for several cases, the mechanism of energy tr…