Abstract: Methods and apparatus for measuring a surface charge distribution and/or electrical properties of entities in a liquid are disclosed. In one arrangement, a liquid (2) is provided in contact with a target surface (4). The liquid (2) contains charged entities (6). A concentration of the charged entities (6) in a region between a probe member (8) contacting the liquid (2) and the target surface (4) is detected at each of a plurality of different positions on the target surface (4). A surface charge distribution on the target surface (4) is determined using the detected concentrations.

Abstract: In a method for determining charge and/or size of an object (15) suspended in a fluid, the object (15) is introduced, together with the fluid, into an electrostatic trap (1) defining an electrostatic confining potential. The thermal motion of the object (15) in the fluid is observed under influence of the confining potential, and charge and/or size are determined from the observed thermal motion. In particular, the viscous drag on the object yields a measure of its size, while the stiffness of its confinement can be compared with a potential model to reveal the total charge it carries. Also disclosed are an apparatus and software for carrying out the method.

Abstract: The invention relates to a device for orienting at least one object in at least a first or a second orientation or for placing it in a first or a second spatial location, comprising: a substrate (10) having a surface (10a), at least one object (3) levitated above said surface (10a),wherein the device (1) is designed to generate an e.g. electrostatic potential with help of the substrate (10) for trapping the at least one object (3), the potential having at least a first minimum and a second minimum, so that the at least one object (3) is oriented in the first orientation (or located in a first spatial location) when being trapped in the first minimum, and in the second orientation (or located in the second spatial location) when being trapped in the second minimum, and wherein said at least one object (3) is trapped in one of said minima.

Abstract: In a method for determining charge and/or size of an object (15) suspended in a fluid, the object (15) is introduced, together with the fluid, into an electrostatic trap (1) defining an electrostatic confining potential. The thermal motion of the object (15) in the fluid is observed under influence of the confining potential, and charge and/or size are determined from the observed thermal motion. In particular, the viscous drag on the object yields a measure of its size, while the stiffness of its confinement can be compared with a potential model to reveal the total charge it carries. Also disclosed are an apparatus and software for carrying out the method.

Abstract: The present invention provides methods and systems for running reactions, in particular, biological reactions and assays, in a Rayleigh-Bénard convection cell. The utilization of Rayleigh-Bénard convection principles for conducting biological or biochemical reactions is a novel application. In order to use Rayleigh-Bénard convection for conducting biological or biochemical reactions it is necessary to create a temperature differential in a solution of reactants.

Abstract: The present invention provides methods and systems for running reactions, in particular, biological reactions and assays, in a Rayleigh-Bénard convection cell. The utilization of Rayleigh-Bénard convection principles for conducting biological or biochemical reactions is a novel application. In order to use Rayleigh-Bénard convection for conducting biological or biochemical reactions it is necessary to create a temperature differential in a solution of reactants.