Concentration of Virus from Water by Electro-Osmosis and Forced-Flow Electrophoresis. II. Improvement of Methodology and Application to Tap Water

The ability of the Canalco Model CF-3 electro-osmosis (EO) apparatus to concentrate viruses from artificially seeded distilled water was improved. Modification of the physical arrangement of the equipment allowed for a 10–25 fold increase in concentration efficiency and a concomitant decrease in the process time. The major improvements involved modifications of the cell arrangement (which increased the membrane transport area), a change in the salt replenishing solution and the use of different membranes of higher flux. Viruses concentrated by E0 from seeded tap water resulted in lower recoveries when compared to distilled water. The lower yields were probably due to instability or aggregation of the agents in the menstruum and not directly related to the physical apparatus. Under the conditions used, one could detect virus at levels as low as 0.01 plaque forming units (PFU) per ml of initial input. The efficacy of a modification of the Canalco forced-flow electrophoretic (FFE) system was also evaluated. The maximum potential was applied with a constant value for pump rates. A 6-fold concentration of virus and a 12-fold decrease in water volume was obtained.     

Isolation of Four Isomers of the 20,000 Dalton Variant of Human Pituitary Growth Hormone

A simple procedure has been developed which for the first time describes the isolation of isomers of the 20, 000 dalton variant of human growth hormone (20K hGH). From a human pituitary hormone concentrate different hGH dimers (covalently and noncova-lently linked) were enriched by chromatography on SP-Sephadex C-50, DEAE-Sepharose CL-6B and Sephadex G-100. Noncovalently-1inked dimers were split by 6 M urea into 20K hGH and 22K hGH monomers. A complete group-separation of 20K hGH and 22K hGH monomers was achieved by chromatography on DEAE-Sepharose CL-6B at neutral pH. The 20K hGH monomer was resolved into four isomers either by preparative isoelectric focusing or by zone electrophoresis in agarose suspension at alkaline pH. The three latter techniques were all used in the presence of 6 M urea. Radioimmunoassay and radioreceptorassay indicated that the isomers obtained were true components of human growth hormone.     

Removal of Triosephosphate,Isomerase from Albumins

Commercial serum albumin and ovalbumin from a variety of sources contain triosephosphate isomerase activity which can interfere with many enzyme assays and metabolic studies. A simple procedure is described for the removal of this contaminant by preparative electrophoresis or electrofocus-ing.