In analogy to pressure-driven gradient techniques in high-performance liquid chromatography, a system has been developed for delivering electroosmotically driven solvent gradients for capillary electrochromatography (CEC). Dynamic gradients with submicroliter per minute flow rates are generated by merging two electroosmotic flows that are regulated by computer-controlled voltages. These flows a...

Several liquid-chromatographic systems involving anion-exchange resins and linear acetate gradient elution have been reported previously for the analysis of ultraviolet-absorbing constituents in human urine. We describe a high-performance liquid-chromatographic system on which a macroreticular anion-exchange resin, and stepwise elution are used. Separations were more rapid with ammonium chlorid...

Appropriate substitution of acetonitrile (ACN) in mobile phases for reversed-phase liquid chromatography (RPLC) by low toxicity, ecologically friendly alternative solvents emerges as a greener approach in separation sciences. Ethyl lactate is considered as a green solvent in organic synthesis, industrial extraction processes and many other applicative fields. Its ability to substitute ACN in mo...

BACKGROUND Native immunoprecipitation followed by protein A-mediated recovery of the immuno-complex is a powerful tool to study protein-protein interactions. A limitation of this technique is the concomitant recovery of large amounts of immunoglobulin, which interferes with down-stream applications such as mass spectrometric analysis and Western blotting. Here we report a detergent-based "soft"...

New zonal centrifuges can conveniently process as much as five orders of magnitude (10(5)) greater sample volumes than conventional swinging-bucket rotors. The continuous-sample-flow-with-banding versions may be used in series with ancillary purification procedures. Here we have studied the combined process: absorption and elution of influenza virus with barium sulfate followed by concentration...

In this paper, tapping mode atomic force microscopy was applied to visualize the higher order chromatin structure reconstituted from calf thymus DNA and calf thymus whole histone in vitro. All the revealed reconstituted chromatin structures consisted of similar well-defined subunits. In some of the chromatin structures, four to six subunits per turn were wrapped right-handed to form a flattened...