Abstract: A method of positioning a laminar flow of a sample fluid on a surface within a flow cell is disclosed. The method comprises providing a laminar flow of a first guiding fluid adjacent to a laminar flow of a second guiding fluid different from the first guiding fluid such that the two fluids flow together over the surface with a detectable interface to each other; detecting the interface between the two different guiding fluids; optionally adjusting the interface laterally to a desired position by adjusting the relative flow rates of the two guiding fluids; and introducing a laminar flow of the sample fluid between the laminar flows of the first and second guiding fluids such that the flow of the sample fluid is sandwiched between the guiding fluids. An analytical system for carrying out the method, a computer program, a computer program product and a computer system for performing the method are also disclosed.

Abstract: A method and an apparatus for the development of a control process for an instrument are disclosed. The method comprises a first step of selecting one or more commands from a plurality of pre-defined commands in which at least one of the selected one or more commands being a purpose-linked command; and a second step of combining the selected one or more commands to produce the control process. The pre-defined commands have a control part for controlling the operation of the instrument and at least one of the pre-defined commands has a purpose part for controlling the purpose of the command.

Abstract: The invention relates to a computer-implemented method for determining at least one kinetic parameter for the interaction of an analyte in solution with an immobilized ligand from a data set comprising a plurality of different binding curves, each of which represents the progress of the interaction of the analyte with the ligand with time, comprising the steps of: a) performing at least one fit of the whole data set or subsets thereof to a predetermined kinetic model for the interaction; b) based on the result of the fit or fits performed in step a), identifying and excluding binding curves of unacceptable quality; c) performing a final fit to the remaining data set; and d) obtaining therefrom the kinetic parameter or parameters. The invention also relates to an analytical system for carrying out the method, as well as a computer program, computer program product and computer system for performing the method.

Abstract: An optical apparatus for total internal reflection spectroscopy comprises: a transparent body having an internally reflective surface; at least one source of electromagnetic radiation for providing at least one beam of collimated electromagnetic radiation; optical scanning means for directing the beam or beams to the transparent body so that the radiation is internally reflected at the reflective surface, and sequentially or continuously scanning the incident angle of the radiation over an angular range; at least one detector for detecting electromagnetic radiation exiting the transparent body, and means for counteracting variation of the irradiance in the illuminated area of the surface during the angular scan, or the effect of such variation on the reflected beam or beams. An optical apparatus for examining thin layer structures on a surface for differences in respect of optical thickness and/or refractive index, and a method for total internal reflection spectroscopy are also disclosed.

Abstract: A method and apparatus for assaying a drug candidate with a biosensor having one or more sensing surface-bound biomolecules associated therewith are disclosed. The method comprises the steps of measuring the binding interaction between the drug candidate and the one or more sensing surface-bound biomolecules of the biosensor to obtain an estimate of at least one binding interaction parameter of the drug candidate, and then comparing the estimated binding interaction parameter against a mathematical expression correlated from binding interaction data associated with known drug compounds to determine an estimate of at least pharmacokinetic parameter of absorption, distribution, metabolism, or excretion (ADME) that is related to the drug candidate. The present invention allows for the simultaneous measurement of different pharmacokinetic parameters of the drug candidate, as well as an indication of the drug candidate's solubility, by use of a single analytical instrument.

Abstract: The invention relates to a method of characterizing interaction between two species in a liquid environment, wherein a liquid comprising said at least one species is passed as a flow through a measurement system, and wherein the interaction takes place within said measurement system. The method comprises generating a concentration gradient of at least a first one of said species or of at least one other species having an influence on the interaction or on interacted components. The flow of liquid is passed through a sensor device, and a result of interaction between said at least two species is detected. The flow of liquid is intersected at least once with a further liquid before the flow is passed through said sensor, so as to create at least two separated liquid segments having different concentrations of at least one of said species forming the concentration gradient.

Abstract: A method of determining kinetic parameters for a reversible molecular interaction between a ligand immobilized to a solid support surface and a binding partner to the ligand in solution, comprises sequentially, without intermediate regeneration or renewal of the immobilized ligand, flowing a plurality of fluid volumes containing different known concentrations of the binding partner over the solid support surface, monitoring the momentary amount of binding partner bound to the solid support surface related to time and solution concentration of binding partner and collecting the binding data, and determining the kinetic parameters by globally fitting a predetermined kinetic model for the interaction between the binding partner and the immobilized ligand to the collected binding data, which model allows for mass transport limitation at the solid support surface.

Abstract: Methods for capturing analytes associated with surface-bound ligands are disclosed. The methods involve eluting analytes from surface-bound ligands with a first liquid to generate free analytes, and capturing the free analytes with a solid capturing material within the first liquid to generate a first liquid containing captured analytes. The first liquid may be a flowing liquid or a non-flowing liquid, and the surface to which the surface-bound ligand is attached may be a sensing surface, such as a biosensor, or a non-sensing surface. The captured analytes may be further consolidated at a location removed from the surface-bound ligand, eluted from the solid capturing material with a second liquid, and used for subsequent analysis or procedures.

Abstract: A method of examining thin layer structures on a surface for differences in respect of optical thickness, which method comprises the steps of: irradiating the surface with light so that the light is internally or externally reflected at the surface; imaging the reflected light on a first two-dimensional detector; sequentially or continuously scanning the incident angle and/or wavelength of the light over an angular and/or wavelength range; measuring the intensities of light reflected from different parts of the surface and impinging on different parts of the detector, at at least a number of incident angles and/or wavelengths, the intensity of light reflected from each part of the surface for each angle and/or wavelength depending on the optical thickness of the thin layer structure thereon; and determining from the detected light intensities at the different light incident angles and/or wavelengths an optical thickness image of the thin layer structures on the surface.

Abstract: The present invention relates to a method for analysing a cell sample for cell surface-bound or intracellularly bound analytes by providing an array of immobilised specific binding agents for a set of different ligands, where each ligand is specific to a respective cell surface-bound or intracellularly bound analyte, and using the array and the set of ligands in an inhibition type or a direct type assay format to determine cell surface-bound or intracellularly bound analytes in the cell sample. The invention also relates to assay kits for cell characterization.

Abstract: A method of immobilizing a target molecule to a solid support surface capable of interacting with the target molecule is disclosed. The method comprises the steps of complexing the target molecule with a vesicular structure capable of forming a dissociable complex with the target molecule, contacting the complex formed with the solid support surface to thereby bind the target molecule to the surface, dissociating the complex, and removing the vesicular structure from the solid support surface to leave the target molecule immobilized on the surface. A method of sensitizing a solid support surface, the use of the sensitized solid support surface for analyzing analytes, and a reagent kit for carrying out the method are also disclosed.

Abstract: A method and apparatus for assaying a drug candidate with a biosensor having one or more sensing surface-bound biomolecules associated therewith are disclosed. The method comprises the steps of measuring the binding interaction between the drug candidate and the one or more sensing surface-bound biomolecules of the biosensor to obtain an estimate of at least one binding interaction parameter of the drug candidate, and then comparing the estimated binding interaction parameter against a mathematical expression correlated from binding interaction data associated with known drug compounds to determine an estimate of at least pharmacokinetic parameter of absorption, distribution, metabolism, or excretion (ADME) that is related to the drug candidate. The present invention allows for the simultaneous measurement of different pharmacokinetic parameters of the drug candidate, as well as an indication of the drug candidate's solubility, by use of a single analytical instrument.

Abstract: The invention relates to a method of determining the binding site specificity of an analyte to a ligand having at least two different binding sites, which method comprises immobilizing the ligand to a solid support, mixing the analyte with a reversibly binding reference analyte which has a dissociation behaviour that differs significantly from that of the analyte, contacting the mixture with the ligand to determine dissociation characteristics for the mixture, and determining therefrom the binding site specificity of the analyte in relation to the reference analyte. The invention also relates to an analytical system for carrying out the method, and to a computer program, computer program product and computer system for performing the method.

Abstract: Multivariate type assay methods are disclosed which comprise co-immobilizing different groups of ligands on respective discrete areas of a solid support surface, sequentially contacting the different areas with single or multiple analytes, detecting interactions of the analytes with the ligand groups, and determining therefrom the amount of ligand-binding of each analyte.

Abstract: An optical apparatus for total internal reflection spectroscopy comprises: a transparent body having an internally reflective surface; at least one source of electromagnetic radiation for providing at least one beam of collimated electromagnetic radiation; optical scanning means for directing the beam or beams to the transparent body so that the radiation is internally reflected at the reflective surface, and sequentially or continuously scanning the incident angle of the radiation over an angular range; at least one detector for detecting electromagnetic radiation exiting the transparent body, and means for counteracting variation of the irradiance in the illuminated area of the surface during the angular scan, or the effect of such variation on the reflected beam or beams. An optical apparatus for examining thin layer structures on a surface for differences in respect of optical thickness and/or refractive index, and a method for total internal reflection spectroscopy are also disclosed.

Abstract: The present invention discloses a valve integrally associated with a microfluidic transport assembly that is useful for regulating the flow of a liquid sample through an analytical instrument such as, for example, a biosensor.

Abstract: A method of examining thin layer structures on a surface for differences in respect of optical thickness, which method comprises the steps of: irradiating the surface with light so that the light is internally or externally reflected at the surface; imaging the reflected light on a first two-dimensional detector; sequentially or continuously scanning the incident angle and/or wavelength of the light over an angular and/or wavelength range; measuring the intensities of light reflected from different parts of the surface and impinging on different parts of the detector, at at least a number of incident angles and/or wavelengths, the intensity of light reflected from each part of the surface for each angle and/or wavelength depending on the optical thickness of the thin layer structure thereon; and determining from the detected light intensities at the different light incident angles and/or wavelengths an optical thickness image of the thin layer structures on the surface.

Abstract: The present invention relates to a method of coupling multiple binding agents to respective areas of a substrate surface by hydrodynamic addressing, using two laminar fluid flows that flow together in the same direction over the substrate surface with an interface to each other to successively couple the binding agents to the substrate areas, wherein each successive coupling of a binding agent to a surface area is followed or preceded by selective deactivation or activation of a selected surface area according to a defined protocol. The invention also relates to the use of such a binding agent-coupled substrate surface for analytical purposes.

Abstract: The present invention discloses a valve integrally associated with a microfluidic transport assembly that is useful for regulating the flow of a liquid sample through an analytical instrument such as, for example, a biosensor.

Abstract: A method of analysis wherein molecular interactions at one or more sensing surface areas are detected and respective response curves representing the progress of each interaction with time are produced, and wherein a resulting set of response curves is subjected to a quality assessment procedure which comprises representing the response curves with one or more quality descriptors, applying a quality classification method to the descriptors to find outliers, and removing the outliers. The invention also relates to an analytical system including means for classifying the response curves with regard to quality, a computer program for performing the classification, and a computer program product containing the program.