Although electrophoresis is one of the most effective methods for the separation of ionic components of a mixture, the resolving power of different electrophoretic methods is quite variable. To separate two component ions, it is necessary to permit migration to continue until one of the kinds of ions has traveled at least one thickness of the volumes that it initially occupied (the starting zone) further than the other. However, the sharpness, and therefore the resolution, of the zones occupied by each ion diminishes with time because of the spreading of the zones as a result of diffusion. Remarkable resolution has been achieved when advantage is taken of the frictional properties of gels to aid separation by seiving at the molecular level (see Smithies’). A new method, disc electrophoresis, t has been designed that takes advantage of the adjustability of the pore size of a synthetic gel and that automatically produces starting zones of the order of 10 microns thickness from initial volumes with thicknesses of the order of centimeters. High resolution is thus achieved in very brief runs. With this technique, over 20 serum proteins are routinely separated from a sample of whole human serum as small as one microliter in a 20-minute run (see FIGURE 1) . Direct analysis of even very dilute samples becomes routine because the various ions are automatically concentrated to fixed high values at the beginning of the run just prior to separation. Preliminary laboratory studies and theoretic considerations provide evidence of the applicability of this technique to a wide range of ionic species for both analytic and large-scale preparative purposes. Theory has also provided the basis for a simple application of disc electrophoresis to the simultaneous determination of both the free mobility and the aqueous diffusion constant of a protein. This report will detail some mechanisms that provide a rationale for the resolution afforded by zone electrophoresis in many gels; will develop the theory of some new modifications of zone electrophoresis that have been designed to take maximum advantage of these mechanisms; and will provide some examples of the results that disc electrophoresis has produced.

Disc electrophoresis-i background and theory*

High resolution acrylamide gel electrophoresis of histones.

The third helix of the Antennapedia homeodomain translocates through biological membranes

We report the purification from pig brain of a factor supporting the survival of, and fibre outgrowth from, cultured embryonic chick sensory neurons. The purified factor migrates as one single band, mol. wt. 12 300, on gel electrophoresis in the presence of sodium dodecylsulphate (SDS) and is a basic molecule (pI greater than or equal to 10.1). Approximately 1 microgram factor was isolated from 1.5 kg brain. The final degree of purification was estimated to be 1.4 X 10(6)-fold, and the specific activity 0.4 ng/ml/unit, which is similar to that of nerve growth factor (NGF) using the same assay system. This factor is the first neurotrophic factor to be purified since NGF, from which it is clearly distinguished because it has different antigenic and functional properties.

Purification of a new neurotrophic factor from mammalian brain.

Protein damage and degradation by oxygen radicals. I. general aspects.

DISK electrophoresis on small columns of polyacrylamide gels, a new method for the separation of serum proteins, has been developed by Ornstein and Davis1,2.

Disk Electrophoresis of Basic Proteins and Peptides on Polyacrylamide Gels

Pancreatic elastase: purification, properties, and function.

A simple method is described for the preparation of human growth hormone from acetone powders of pituitary glands. Growth hormone preparations were obtained in high yield and with biological activity equal to that of material made by published methods. The material obtained by this procedure proved entirely satisfactory in clinical studies. The only other hormonal activity observed in any concentration is that of prolactin. Human gonadotropins were also obtained in good yield from one of the side fractions.

Human growth hormone: preparation from acetone powder.

https://www.jbc.org/content/234/9/2304.full.pdf

U. J. Lewis

Papers

Disk Electrophoresis of Basic Proteins and Peptides on Polyacrylamide Gels

Pancreatic elastase: purification, properties, and function.

Human growth hormone: preparation from acetone powder.

Pancreatic elastase: differentiation from other pancreatic proteinases.

Crystalline human growth hormone