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Nile Blue (nile + blue)
Selected AbstractsSeparation of Nile Blue-labelled fatty acids by CE with absorbance detection using a red light-emitting diodeELECTROPHORESIS, Issue 8 2007Michael C. Breadmore Dr. Abstract The separation of fatty acids derivatised with Nile Blue (NB) by CE with detection using a red light-emitting diode (LED) was examined. NB was selected as the derivatisation agent due to its high molar absorption coefficient of 76,000,M,1cm,1 at 633,nm, making it well suited for sensitive absorbance detection using a red 635,nm LED. NB-labelled fatty acids were separated by both MEKC using SDS micelles, i -PrOH and n -BuOH and by NACE in a number of solvents including MeOH, EtOH and ACN. The sensitivity of NACE was superior to MEKC, with detection limits of 5×10,7,7×10,7,M obtained for each acid, approximately 20 times lower than the MEKC method. The NACE detection limits are approximately 100 times lower than previous reports on the separation of fatty acids by CE using indirect absorbance detection, ten times lower than using indirect fluorescence detection and are inferior only to those obtained using precapillary derivatisation and direct fluorescence detection. The efficiency of the NACE method was also superior to MEKC and allowed the separation of unsaturated fatty acids to be examined, although it was not possible to baseline-resolve linoleic (C18:2) and linolenic (C18:3) acids in a reasonable time. The method was used to analyse the fatty acid profile of two edible oils, namely sunflower and sesame oils, after alkali hydrolysis, where it was possible to identify both the saturated and unsaturated fatty acids in each sample. [source] Production of monodisperse silver colloids by reduction with hydrazine: the effect of chloride and aggregation on SER(R)S signal intensity,JOURNAL OF RAMAN SPECTROSCOPY, Issue 2 2004U. Nickel Abstract SER(R)S spectra with high signal intensity of Nile Blue A sulfate and 1,1,-diethyl-2,2,-cyanine iodide present in low concentration (,0.05 µM) can be recorded by employing certain silver sols in the absence of any chloride and without highly aggregated particles. The sols have been prepared by reduction of silver nitrate with hydrazine hydrate in a special procedure at a carefully established pH. In the presence of chloride, the maximum SER(R)S signal observed for a ca. 0.5 µM solution of Nile Blue A is of similar magnitude employing either a silver sol according to Lee and Meisel or our sol C, which contains nearly exclusively single silver particles with diameters of about 50 nm. Without added chloride, however, only our sol produces SER(R)S spectra with similar intensity as with chloride. Because the influence of chloride and coagulation on the intensity of the SER(R)S-signal can be controlled by varying the additives to our silver sol, further experiments of this kind can help to elucidate how these two parameters influence the magnitude of the SERS enhancement. Copyright © 2004 John Wiley & Sons, Ltd. [source] Waveguiding, absorption and emission properties of dye-impregnated oxidized porous siliconPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 5 2007D. Navarro-Urrios Abstract The waveguiding, absorption and emission properties of oxidised porous silicon waveguides when impregnated with Nile Blue have been studied. We present m-line measurements before and after the impregnation showing that the effective indices of the modes remain the same. When performing guided luminescence experiments, a structured emission band is measured. Using the refractive index profile extracted from m-line measurements it has been possible to simulate the emission lineshape assuming the observation of an interference pattern formed across the waveguide. We demonstrate that these oscillations appear because in the first hundreds of nanometers the dye concentration is several orders of magnitude higher than in the rest of the sample. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Perturbation of retinoic acid (RA)-mediated limb development suggests a role for diminished RA signaling in the teratogenesis of ethanol,,§BIRTH DEFECTS RESEARCH, Issue 9 2007Corey S. Johnson Abstract BACKGROUND: A proposed mechanism for ethanol teratogenicity entails ethanol-mediated reductions in retinoic acid (RA). This premise was investigated utilizing a mouse model, with limb reduction defects as the teratogenic end point. METHODS: Ethanol, Disulfiram, or BMS-189453 was administered to C57BL/6J mice on the 9th day of pregnancy. Forelimb morphology was assessed on gestation day 18 using Alcian blue and Alizarin red staining. Nile blue sulfate or LysoTracker Red (LTR) vital staining identified cell death in the limb bud. The ability of RA to prevent ethanol-induced cell death was assessed by coadministration followed by laser scanning confocal microscopic examination of LTR-staining. In situ hybridization and qPCR were used to examine gene expression in treated limb buds. RESULTS: Ethanol, Disulfiram, and BMS-189453 resulted in postaxial ectrodactyly, intermediate ectrodactyly, and other digital defects. Excessive Nile blue sulfate staining was evident in the presumptive AER following each of the three exposures. Ethanol-induced LTR staining was prevented by RA supplementation. Both in situ hybridization and qPCR illustrated decreases in Shh and Tbx5 in ethanol-exposed embryos as compared to control. CONCLUSIONS: Contrary to studies of prolonged RA deficiency, acute exposure to functional antagonists of RA results in limb defects that are morphologically similar to those caused by ethanol. The rescue of ethanol-induced cell death by RA and similar changes in Shh transcription further suggest that RA contributes to ethanol-induced limb dysmorphology. Moreover, the repression of key mediators of limb development soon after ethanol exposure adds to the existing knowledge of the pathogenic effects of ethanol. Birth Defects Research (Part A), 2007. © 2007 Wiley-Liss, Inc. [source] | ||||||||||