Abstract: A method and apparatus for performing separation of molecules, in particular biomolecules such as nucleic acids and peptides, are disclosed. The method comprises separating molecules by a first characteristic along a linear dimension of a channel, and separating the molecules by a second characteristic along the same linear dimension, with the rust and second separations being carried out within at least partially overlapping sections of the channel. The two separations may then be combined to give a virtual two-dimensional separation which is carried out in a single dimensional real space. The method may also include detecting molecules during the second separation, preferably using an intrinsic characteristic of the molecules for example UV absorbance.

Abstract: A separating device for use in separating electrically charged components, e.g., by electrophoresis, comprises a channel branched at a branch point to provide a main feed channel (105) connected to at least two subsidiary channels (110, 115). In use, different components (120, 125, 130) show differential migration along the feed channel (105) so they can be separated into different subsidiary channels (110, 115) at the branch point. To support this separation, the separating device is provided with switchable voltage control means for controlling local voltages in a region of the branch point to provide potential differences of opposing polarity along the respective subsidiary channels (110, 115) such that a component to be separated (125) can be caused to migrate from the feed channel into a different subsidiary channel (115) from one or more other components.

Abstract: An apparatus and method for analysing temperature-dependent molecular configurations such as folding comprises a multi-channel flow-through chip (12) along which molecules to be analysed pass. A temperature gradient is maintained along the length of the chip. As molecules pass along the channels they fold or unfold, in response to the changing temperature. These changing molecular configurations are investigated by simultaneously measuring the extent to which the molecules absorb UV light, and the extent to which they fluoresce. The absorption and fluorescence information is supplied to a computer system (26) for real-time analysis.

Abstract: A system for separating biological molecules includes a chip (10) on which there is an electrophoresis separation microchannel (16). At the start of the channel there is an isoelectric focusing section (14) containing a gel having a pH gradient. Molecules to be separated are placed in the focusing section (14) and move to an equilibrium position under the influence of an electric field. The electrophoretic state of the molecules is then changed, and a high voltage potential applied across the entire length of the focusing and separation sections. The molecules migrate under the influence of the electric field from the focusing section into the separation section where their position and velocity are tracked. From a knowledge of position and velocity, a user can determine both charge/mass ratio and isoelectric equilibrium point for each molecule. The gels can be replicated in the chip to allow parallel analysis, and hence comparisons, to take place.

Abstract: A separating device for use in separating electrically charged components, e.g., by electrophoresis, comprises a channel branched at a branch point to provide a main feed channel (105) connected to at least two subsidiary channels (110, 115). In use, different components (120, 125, 130) show differential migration along the feed channel (105) so they can be separated into different subsidiary channels (110, 115) at the branch point. To support this separation, the separating device is provided with switchable voltage control means for controlling local voltages in a region of the branch point to provide potential differences of opposing polarity along the respective subsidiary channels (110, 115) such that a component to be separated (125) can be caused to migrate from the feed channel into a different subsidiary channel (115) from one or more other components.

Abstract: An apparatus and method for analysing temperature-dependent molecular configurations such as folding comprises a multi-channel flow-through chip (12) along which molecules to be analysed pass. A temperature gradient is maintained along the length of the chip. As molecules pass along the channels they fold or unfold, in response to the changing temperature. These changing molecular configurations are investigated by simultaneously measuring the extent to which the molecules absorb UV light, and the extent to which they fluoresce. The absorption and fluorescence information is supplied to a computer system (26) for real-time analysis.

Abstract: A centrifugal spectrometer has a solid rotor (10) formed within which there are cavities or blades (12). In use, each blade is filled with a buffer solution, and a sample to be separated is placed in a sample well (32) at the end of a separation channel (24). The rotor is spun at a controlled velocity and, at the same time, a controlled potential difference is applied along the length of the blade. The blade shape causes the resultant electric field to vary as a function of radial distance. The sample separates out into bands, which move along the channel (24) under the combined influence of the centrifugal force and the varying electric field. The bands focus at differing equilibrium points according to their charge/mass ratios. The band positions are determined by a readout head (36). The dynamic range of the device may be controlled by altering the rotational velocity and the voltages that are applied.

Abstract: An analyser comprises a substrate (20) of diamond, sapphire or a polymer material; an array (10) of elongate capillary channels formed in the substrate; means (40) for driving a sample to be tested along one or more of the channels whereby the velocities of components of the sample along the channels depends on the relative molecular weights of those components; and a radiation source (100) and a radiation detector (30) disposed on either side of the channel array so as to detect the presence of material in the channels as interruptions in the radiation path between the radiation source and the radiation detector.