Detection of transient and steady states in electrophoresis: Description and applications of a new apparatus with 255 potential gradient detectors along the separation trough

Introduction of a linear of detectors along the electrophoretic separation space permits monitoring the evolution of electrophoretic zone structures, fully controlled by a microprocessor system. Both transient and steady state zone structures can be recognized. A description of our capillary type apparatus, with 255 potential gradient sensors measuring the most general physical property characterizing the separand pattern in electrophoresis, is given. The central unit of this device is a unique pattern of 256 electrodes. They are chemically photoetched on a supporting glass plate from a vapor-deposited thin layer of a conductor. Each sensor has a width of 60 μm, a height of about 0.1μm and they are spaced 340 μm apart. The whole separation cell, appropriate detection electronics and a new constant current high tension power supply are described together with the microcomputer system used for control and data treatment. Illustrations of detected zone structures with steady state moving boundaries are given in terms of isotachophoretic and moving boundary experiments. The monitoring of non-steady state boundaries is shown by following sample zones in zone electrophoresis.