Motoneurons from E14 rat embryos have been retrogradely labeled with the carbocyanine derivative dil and purified 12-fold by centrifugation on a density gradient made of Nycodenz, as assessed by the increase in CAT activity per cell and in the percentage of dil-labeled cells. A 20- to 36-fold purification was achieved by the microdissection of the labeled lumbar motor columns followed by densit...

Proteoglycans were isolated from cartilage by extraction with 4M-guanidinium chloride followed by direct centrifugation in 4M-guanidinium chloride/CsCl at a low starting density, 1.34 g/ml. N-Ethylmaleimide was included in the extraction solvent as a precaution against contamination of proteoglycans with unrelated proteins mediated by disulphide exchange. A novel, discrete, low-buoyant-density ...

A procedure has been developed for the quantitative determination of the extraetable proteins of the nit heart. Utilizing extraction with a sucrose-versene solution and employing differential centrifugation, followed by extraction with a phosphate-pyrophosphate buffer, low-ionic-strength extractives, a mitochondrial fraction, and high-ionic-strength extractives have been obtained. Electrophoret...

The separation of compounds by chromatography is often followed by the need to separate the compounds from the stationary phase for quantification, rechromatography, or other analytical procedures. In thin-layer chromatography compounds are usually separated from the adsorbent by removal of the layer from the backing by scraping or suction, followed by elution of the compounds in columns or by ...

Several methods have been evaluated for the separation of red cells of different ages on the basis of density differences. Simple sedimentation and flotation technics have been found to be unsatisfactory. Centrifugation, followed by a modified sampling procedure, has been demonstrated to provide excellent separation of erythrocyte populations of different ages. Standardization of centrifuge con...

We present the preparation of disk-like graphene nanoflakes, highly dispersible in dimethylformamide (DMF), with uniform size and thickness. The preparation procedure includes an overnight mild sonication of natural graphite in DMF, followed by a purification step using ultra-centrifugation. The mean diameter of the as produced well defined round shaped graphene nanoflakes is about 100 nm and t...

In a variation of standard DNA extraction methods, Nocardia asteroides was repeatedly exposed to sodium dodecyl sulfate at 60 degrees C for 30 min; each extraction was followed by centrifugation, removal of the nucleic acid-rich supernatant, and suspension of the cell pellet in fresh sodium dodecyl sulfate. The pooled supernatants contained a substantially higher amount of DNA than the first su...

Separation of short single- and double-stranded DNA typically requires gel electrophoresis followed by DNA extraction, which is a time consuming process. Graphene oxide adsorbs single-stranded DNA more quickly than double-stranded ones, allowing for selective removal of the former with a simple mixing and centrifugation operation. The effect of DNA length and salt on adsorption selectivity has ...

A fraction containing a protein-glycogen complex was obtained from rabbit muscle by different procedures involving acid precipitation followed by differential centrifugation, direct differential centrifugation, and acetone fractionation. All three preparations were essentially identical in terms of their physical, chemical, and enzymatic characteristics strongly suggesting that the protein-glyc...

The purpose of this study was to characterize highly enriched human spermatozoa membrane proteins by two-dimensional electrophoresis and computer image analysis. Sperm membrane proteins were extracted by detergent solubilization from three different preparations: 1) washed semen cells following centrifugation and three wash steps in Ham's F-10 medium (the standard sperm preparation, which is co...