Abstract: A device for amperometric adjustment of an ion concentration in an adjustment solution comprises at least three chamber-shaped electrolyte regions, each with a control electrode and diffusion depressant means and which can be filled with electrolytes, whereby all electrolyte regions can be brought into contact with the adjustment solution in such a way that, when current flows through the control electrodes, ions can be transported from the electrolyte solutions through the diffusion depressant means into the adjustment solution or in the reverse direction, and means for supplying each electrolyte region with control currents. The device is designed for adjusting the pH value and/or an ion concentration of the adjustment solution different to the hydrogen ion concentration. At least two or all electrolyte regions are supported by a joint holding means.

Abstract: A method and a device for position and/or type-selective control of the position and/or change of position of suspended particles in a multielectrode system by the effect of polarization forces that are induced in the particles by alternating electric fields in the multielectrode system, which particles comprise biological or synthetic objects with dimensions essentially corresponding to those of biological cells or cell organelles, viruses or macromolecules, base on the fact that the multielectrode system forms with the particle suspension an electrical network, in which means of resonance are provided for creating a resonant increase or damping of the field strength of the alternating electric fields at certain frequencies in at least one locally demarcated region of the multielectrode system.