The Purification of Formol Diphtheria Toxoid by Multi-Membrane Electro-Decantation

Abstract

Summary Formol diphtheria toxoid was purified by a combination of multi-membrane electro-decantation, ammonium sulphate fractionation and acid precipitation, yielding a product with a potency of 2950 Lf/mg protein nitrogen without impairing the antigenieity in guinea-pigs. Physieochemical investigation showed that the purified toxoid was homogeneous by gel diffusion, electrophoresis, diffusion and sedimentation measurements. Using sedimentation and diffusion data a molecular weight of 73,300 and a frictional ratio of 1.34 were calculated. The iso-electric point of formol diphtheria toxoid, as determined by a new method using a modified form of M.M.E.D. apparatus, was found to be pH 4.15 and pH 4.25 in acetate buffers of ionic strengths 0.05 and 0.025 respectively.

Treatment of Alumina and Silica Chemical Mechanical Polishing Waste by Electrodecantation and Electrocoagulation

“…The electrodecantation mechanism has been applied to the separation of gold sols, 20 proteins, [21][22][23][24][25][26] and viruses. 27,28 Variations have been exploited to facilitate the separation of a variety of colloidal matter. For example, particles with a specific gravity less than the surrounding medium tend to accumulate at the top of the vessel, and rubber latex has been collected as a cream in this way.…”

“…29,30 The passage of an electric current has no effect on uncharged material; this allows the separation of mobile particles from those at their isolectric point. 22 Multiple membrane devices 28,31 and semicontinuous/continuous flow designs 29,32 have also been developed. Many of these approaches have been adapted to industrial-scale applications.…”