Aids for the Optical Analysis of Electrophoretic Diagrams.
Kurt Guenter Stern, Delafield DuBois · PubMed · 1941
Studies of the electrophoresis of colloids by the moving boundary method ' have been greatly stimulated by the recent contributions of A. Tiselius.8 The new electrophoresis cell of Tiselius is built up of rectangular, cemented glass compartments which may be shifted with respect to each other by sliding on greased, ground surfaces. The connections with the electrode vessels are made with rubber sleeves. While this construction is necessary for the actual separation of mixtures of colloids, such cells are expensive, the preparation of each experiment is a lengthy procedure, and the various junctions between the individual elements are potential sources of electrical and fluid leaks. In experiments, however, L where only an optical analysis of colloid mixtures, with regard to their electrochemical homogeneity, number of components, mobility, or concentration is desired, a simpler arrangement may be used. Thus, the cylindrical U-tube cell described earlier Fiar 1o Modified Tiseius elecby Tiselius ' has been used in this laboratory over a period of two years for the optical analysis of a variety of protein systems, with satisfactory results. Since only visible light is employed in the Toepler schlieren method, the quartz parts of the original cell were replaced by 9 mm. Pyrex glass tubing, selected for uniformity of bore and freedom from air bubbles. This cell can be made in one piece, eliminating all rubber and grease connections. Lately, the portion of the U-tube in which the migration of protein boundaries is to be observed, has been replaced by two chambers of rectangular cross-section as shown in Fig. 1. The side walls of these