The construction and operation of a preparative polyacrylamide-gel electrophoresis system is described. Emerging protein bands are collected by an intermittent pumping system which is based on the design of Brownstone ((1%9) Anal. Biochem.
27, 25-46). The original pressure-sensitive operation was, however, simplified to time-volume operation. Cooling of the gel by a central cooling finger. essentially according to Jovin et al. ((1964) Anal.
Biochem. 9, 351-369). has also been added. To accomodate the polyethylene tubing needed for intermittent collection of protein and also the central cooling finger. it is necessary to polymerize the gel in a mold before it is installed in the gel housing compartment of the electrophoresis cell. Gel concentrations of 5% and higher can be used in this system. Dilution of emerging protein samples by the intermittent collection system is kept to a minimum. This fact. together with simplicity of design makes it suitable for general preparative work with polyacrylamide-gel electrophoresis. Operation of the apparatus and resolution of protein bands are demonstrated by separation of bovine serum albumin polymers and thyroxine-binding proteins in human serum.
' A preliminary report has been presented before the 50th meeting of the Experimental Biology Group (1974) S. Afr. J. Sci. 70, 252. 363 CopyrIght 0 1976 hy Academic PI-C\. Inc. All right\ of reproductmn in any form reerved.