The aim of this study was to compare invasive and non-invasive strains of Shigella flexneri isolated from Tehran by a 120 kDa protein band by SDS-PAGE, electron microscopy of cell culture and Congo red dye methods. Methods: S. flexneri strains were isolated by standard bacterial methods from fecal specimens of children attending to the 3 children’s hospitals. Phenotype analysis for screening v...

India has a very rich diversity and plantkingdom is certainly a treasure house of diverse natural products. One such product from nature is the dye. In this study, natural colorants mainly flavonoids and carotenoids present in the Marigold flower (TageteserectaL.) were extracted using Soxhlet extraction method and other conventional techniques under different operating conditions. Spectrophotom...

Hydroxyapatite/titania nanocomposites (TiHAp) were synthesized from a mixture of a titanium alkoxide solution and dissolution products of a Moroccan natural phosphate. The simultaneous gelation and precipitation processes occurring at room temperature led to the formation of TiHAp nanocomposites. X-ray diffraction results indicated that hydroxyapatite and anatase (TiO2) were the major crystalli...

The performance of a new dye-sensitized solar cell (DSSC) based in a natural dye extracted from the Bougainvillea spectabilis' bracts, is reported. The performance of this solar cell was compared with cells prepared using extract of the Bougainvillea glabra and mixture of both extracts; in both cases the pigments were betalains, obtained from Reddish-purple extract. These dyes were purified to ...

Restriction enzyme fragmentation and recombinant DNA technology offer powerful tools with which to study gene structure, organization, and expression. Frequently in these studies the need arises to purify on a preparative scale a specific DNA molecule from a mixture. The two most commonly used procedures in such purification are isopycnic centrifugation in dye-salt gradients and gel electrophor...

Since the first observation of electron-beam excited superradiant emission from the organic dye POPOP in the vapor phase buffered by high-pressure pure argon [1 ] , there has been considerable interest in developing this system into an efficient and powerful UV-visible tunable laser [2,3]. In order to establish optimum electron-beam excitation conditions for the organic dye vapor-buffer gas mix...

Characterization of cells comprising solid tumors will facilitate the rational design of cancer chemotherapy for individual patients. We have prepared cell suspensions from human melanoma, sarcoma, and lung tumors by thinly slicing the tissue with a microtome and scalpels (mechanical release), followed by treatment with a mixture of collagenase II and DNase I (enzymatic release). This method of...

We describe the pre-staining of proteins in normal human serum with Remazol Brilliant Blue before separation by disc electrophoresis. Critical to reproducibility are: dye concentration of 0.16 mol/L in a Tris-glycine buffer (pH 8.3), use of equal volumes of serum and dye solution, a tagging period of 2 h at room temperature, and electrophoresis of 0.1 mL of the mixture at 2.5 mA/gel for about 2...

Several preparations of urobilin and stercobilin were investigated with regard to their value as standards for the determination of urobilinogen and urobilin in biologic specimens. Products of commercial origin were found to be impure and therefore unsuitable for this purpose. Absorptivities were measured for solutions of the pigments in 3% FICI in methanol and for the chromogens, obtained by f...

Water plays a vital and essential role in our ecosystem. This natural resource is becoming scarce, making its availability a major social and economic concern. Use of a large variety of synthetic dyes in textile industries has raised an hazardous environmental alert. About 17 20% of freshwater pollution is caused by textile effluents. These effluents are recalcitrant to biodegradation and cause...