Abstract: In order to isoelectrically separate particles with a pH-dependent net charge, the particles are exposed in a guiding liquid to electric field forces. The pH value of the guiding liquid is set in such a way that at least one predetermined type of particle is separated from the remaining particles and migrates to a fixing collecting means under the effect of the electric field forces. The collecting means is for example a porous hollow fiber delimited by electrodes which generate the electric field forces and crossed by the guiding liquid together with the sample to be separated. The particles whose isoelectric point matches the pH value of the guiding liquid run unimpeded through the fibers, whereas the remaining particles are pressed against the inner wall of the fiber and are prevented from being carried away with the liquid flow.

Abstract: The invention relates to measuring the concentration of analytes with the aid of an oxidase in an immersion sensor situated in a fluid or in a matrix containing fluid. Oxygen diffuses into the enzyme layer from within, from a gas-filled space connected to the atmosphere and/or to an oxygen reservoir. This enables oxygen saturation of the oxidase in a low-oxygen or oxygen-free medium and/or at high analyte concentrations. The analyte diffuses into the enzyme layer in a channel or a number of channels which contain(s) water and limit(s) diffusion, wherein the channel/channels on the surface of the sensor is/are filled with a protein-impermeable, hydrophilic matrix. By increasing the channel cross-section on the surface of the sensor and/or by connecting the channel/channels to a protein-impermeable, porous, hydrophilic layer on the surface of the sensor, the effect of outer deposits on the diffusion resistance of the analyte is reduced.

Abstract: A method and apparatus for determining solute levels by affinity viscosimetry involving a sensitive fluid, in which the sensitive fluid flows continuously through a first hydraulic resistor in the flow direction of the dialysis chamber, and the sensitive fluid modified by dialysis simultaneously flows through another resistor, wherein the pressure differences between the resistors is determined on-line with the aid of pressure sensors and converted into a relative value which is approximately proportional to the concentration of solute.

Abstract: A method and apparatus for determining solute levels by affinity viscosimetry involving a sensitive fluid, in which the sensitive fluid flows continuously through a first hydraulic resistor in the flow direction of the dialysis chamber, and the sensitive fluid modified by dialysis simultaneously flows through another resistor, wherein the pressure differences between the resistors is determined on-line with the aid of pressure sensors and converted into a relative value which is approximately proportional to the concentration of solute.

Abstract: The invention concerns a process for affinity viscosimetry and a viscosimetric affinity sensor on the basis of sensitive liquids with analyte-dependent viscosity which are localized within a perfusable dialysis chamber and contain colloidal constituents which are cross-linked by affinity bonds. The viscosimetric affinity sensor according to this invention is characterized by the spatial or temporal separation of analyte diffusion from the measurement of the flow resistance for such sensitive liquid flowing through a capillary, needle-like body or other liquid conductor, which integrated combination of a dialysis chamber with viscosimeter enables a researcher to make measurements under lab conditions that provide spatial separation of the dialysis process from the rheological analysis, as done under test conditions where the maximum shear rate of sensitive liquid in the viscosity sensor is at least twice that shear rate of sensitive liquid experienced in the dialysis chamber.

Abstract: The invention relates to a micro-dialysis probe which includes a supply line (1) and a drainage line (6) for a drip-feed solution and a dialysis section, wherein the flow channel for the drip-feed solution experiences an inversion in the area of the dialysis section between the supply line (1) and the drainage line (6), and wherein both the supply line (1) and the drainage line (6) are respectively arranged as separate hollow channels on the outer wall of the probe, side by side, in particular parallel.

Abstract: An apparatus for measuring the viscosity of a fluid having a first rigid member extending from a body of semiconductor material and provided with a first conductive path and a second resiliently flexible member provided with a second conductive path and arranged in cantilever fashion over the rigid member. At least one of the conductive paths may be selectively energized to brig about relative movement between the rigid and flexible member. Subsequent deenergization of the path causes the resiliently flexible member to return to its initial position, the rate of return being measured to derive a signal representative of the viscosity. Also described are methods of carrying out the measurement and of fabricating the apparatus.

Abstract: The invention concerns a process for affinity viscosimetry and a viscosimetric affinity sensor on the basis of sensitive liquids with analyte-dependent viscosity which are localized within a perfusable dialysis chamber and contain colloidal constituents which are cross-linked by affinity bonds. The viscosimetric affinity sensor according to this invention is characterized by the spatial or temporal separation of analyte diffusion from the measurement of the flow resistance. An important advantage of the invention consists in small volume-displacement and negligible structural change within the matrix to be investigated.

Abstract: The invention concerns a process for affinity viscosimetry and a viscosimetric affinity sensor on the basis of sensitive liquids with analyte-dependent viscosity which are localized within a perfusable dialysis chamber and contain colloidal constituents which are cross-linked by affinity bonds. The viscosimetric affinity sensor according to this invention is characterized by the spatial or temporal separation of analyte diffusion from the measurement of the flow resistance for such sensitive liquid flowing through a capillary, needle-like body or other liquid conductor, which integrated combination of a dialysis chamber with viscosimeter enables a researcher to make measurements under lab conditions that provide spatial separation of the dialysis process from the rheological analysis, as done under test conditions where the maximum shear rate of sensitive liquid in the viscosity sensor is at least twice that shear rate of sensitive liquid experienced in the dialysis chamber.

Abstract: A microsensor for the determination of glucose and other analytes in liquids, based on affinity viscosimetry. The sensor based on affinity viscosimetry with stable working properties can be sufficiently minaturized for implantation in the organism. The sensor has a completely closed liquid conducting system having a dialysis chamber of a dialysis hollow fiber filled with the aqueous polymer system, and a measuring system for electrical signal transduction working in such a way that the sensitive polymer solution and eventually other liquids which are not miscible but hydraulically coupled with the polymer solution, are able to move on a closed path. The measuring system contains a micromotor to induce the liquid movement and a signal transducer sensitive to either pressure, volume or streaming to form signals related unequivocally to viscosity.