Search results for "dyes"
showing 10 items of 324 documents
Gold( i )–BODIPY–imidazole bimetallic complexes as new potential anti-inflammatory and anticancer trackable agents
2017
International audience; Two new gold(I)–BODIPY–imidazole based trackable therapeutic bimetallic complexes have been synthesized and fully characterized. They display strong antiproliferative properties on several types of cancers including colon, breast, and prostate and one of them presents a significant anti-inflammatory effect. Additionally, the two compounds could be visualised in vitro by confocal microscopy in the submicromolar range.
Growth of immobilized DNA by polymerase: bridging nanoelectrodes with individual dsDNA molecules.
2011
We present a method for controlled connection of gold electrodes with dsDNA molecules (locally on a chip) by utilizing polymerase to elongate single-stranded DNA primers attached to the electrodes. Thiol-modified oligonucleotides are directed and immobilized to nanoscale electrodes by means of dielectrophoretic trapping, and extended in a procedure mimicking PCR, finally forming a complete dsDNA molecule bridging the gap between the electrodes. The technique opens up opportunities for building from the bottom-up, for detection and sensing applications, and also for molecular electronics.
Electronic and Functional Scope of Boronic Acid Derived Salicylidenehydrazone (BASHY) Complexes as Fluorescent Dyes
2017
[EN] A series of boronic acid derived salicylidenehydrazone (BASHY) complexes was prepared and photophysically characterized. The dye platform can be modified by (a) electronic tuning along the cyanine-type axis via modification of the donor-acceptor pair and (b) functional tuning via the boronic acid residue. On the one hand, approach (a) allows the control of photophysical parameters such as Stokes shift, emission color, and two-photon absorption (2PA) cross section. The resulting dyes show emission light-up behavior in nonpolar media and are characterized by high fluorescence quantum yields (ca. 0.5-0.7) and brightness (ca. 35000-40000 M-1 cm(-1)). Moreover, the 2PA cross sections reach …
Systematic study of SYBR green chromophore reveals major improvement with one heteroatom difference
2021
Five nucleic acid binding cyanine dyes were synthesized and their photophysical properties were evaluated. Changing a single heteroatom in the chromophore causes major differences both in brightness and photostability between the dyes. With such alteration, the brightness of the chromophore increased two-fold compared to the one found in SYBR Green I.
Ocher and cinnabar in the argaric funerary record
2012
The known cases of Bronze Age Argaric stained skeletons found in the Southeast of the Iberian Peninsula, have been analysed. The various hypotheses proposed relating to the origin of these colorations have been evaluated in light of new data provided by SEM, XRD and RAMAN spectroscopic analysis carried out on five Argaric graves of Murcia and Alicante. The results have indicated the presence of ochre and cinnabar on some of the skeletons. Without discarding the possibility that both substances were used in dyeing fabrics, it is proposed that their main use was for face and body make-up, being higher the number of recorded cases on female skeletons compared to male.
Stimulation of endothelial nitric oxide synthase by proinsulin C-peptide.
2003
There is increasing evidence for biological functions of human C-peptide. Recently, we have described that proinsulin C-peptide increases nutritive capillary blood flow and restores erythrocyte deformability in type 1 diabetic patients, whereas it has no such effect in non-diabetic subjects. The aim of the current study was to elucidate cellular mechanisms of this vasodilator effect in vitro by measuring the nitric oxide (NO)-mediated increase of cGMP production in a RFL-6 reporter cell assay and by demonstrating endothelial calcium influx with the Fluo-3 technique. C-peptide increased the release of NO from endothelial NO synthase (eNOS) in bovine aortic endothelial cells in a concentratio…
Study of surface carbohydrates on isolated Golgi subfractions by fluorescent-lectin binding and flow cytometry
1995
The Golgi complex is a functionally heterogeneous subcellular structure that plays a key role in the synthesis, maturation, and sorting of newly synthesized glycoproteins. Fluorescent lectins have been used extensively to analyze surface glycoproteins by flow cytometry in whole cells and more recently in isolated subcellular organelles, such as mitochondria and chloroplasts. We report here the use of several fluorescein-isothiocyanate-conjugated lectins to detect and quantify specific surface sugars by flow cytometry on isolated elements from purified cis and trans-Golgi fractions from rat liver. Our results show that this approach may be useful to study Golgi composition and function, sinc…
Thermodynamic analysis of binding between drugs and glycosaminoglycans by isothermal titration calorimetry and fluorescence spectroscopy
2007
The thermodynamics of the interaction of positively charged drug molecules with negatively charged glycosaminoglycans (GAGs) is investigated by isothermal titration calorimetry (ITC) and fluorescence spectroscopy. The drugs considered are propranolol hydrochloride, tacrine, and aminacrine, and the polymers used as model GAGs are dextran sulfate, chondroitin sulfate, and hyaluronic acid. The ITC results show that the interaction between drugs and GAGs is via direct binding and that GAGs bind to drugs at one set of sites. Large negative values of heat capacity change (DeltaC(p)) are observed upon binding of GAGs to drugs. Such negative DeltaC(p) is not expected for purely electrostatic intera…
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…
Cryopreservation of Escherichia coli K12TG1: Protection from the damaging effects of supercooling by freezing
2015
Injuries in living cells caused by water freezing during a freeze-thaw process have been extensively reported. In particular, intracellular water freezing has long been incriminated in cell death caused by a high cooling rate, but this supposition could not always be demonstrated. This work aims to discriminate the role of water freezing, dehydration and cold-induced injuries in cellular damage occuring during cryopreservation. For this purpose, Escherichia coli K12TG1 suspensions were maintained in a supercooled or frozen state at -20°C for times ranging from 10 min to 5 h. The supercooled state was maintained for a long period at -20°C by applying a non-injurious isostatic pressure (P<40 …