Abstract: The present invention relates to a method for biotinylating a desired subset of a larger population of proteins, wherein the subset of proteins is first selectively bound to a solid phase, thereby separating it from undesired proteins of the population, and then, still bound to solid phase, it is biotinylated. Unreacted biotin may then be washed from the solid phase, and the biotinylated protein may be uncoupled from the solid phase.

Abstract: A method for combining magnetic and centrifugal extraction techniques in a manner that improves wash efficiency and reduces the relative disadvantages of stand alone magnetic or centrifugal systems is provided. Centrifugation occurs about the rotational axis of a generally circular container with generally vertical sides featuring an inward protruding physical feature designed to retain material that exceeds the density of supernatent liquid and that is bound to magnetic particles during the centrifugation. During centrifugation, an external magnetic field is applied about the rotational axis of the container such that magnetic lines of force penetrate the container in any desired location. The magnetic and centrifugal forces may be independently modulated or modulated in relative unison to suit the hydrodynamic characteristics of a given complex.

Abstract: The invention relates to a process for producing ferrofluid-forming magnetic particles substituted by DMSA (FFSH) that can be covalently coupled, directly or through a difunctional reactant, to an effector, which process comprises combining DMSA with ferrofluid-forming magnetic particles to form FFSS particles having disulfide bonds, and reducing the disulfide bonds of the FFSS at basic pH to form FFSH. The invention includes a composition comprising such FFSH magnetic particles. The invention also relates to a method in which FFSH magnetic particles are incubated with an effector comprising at least one functional group which forms an S--S, C--S, C--C, or C--N bond with DMSA, so that a covalent effector-FFSH complex is formed. The invention further includes a method for separating and/or distinguishing between molecules or cells having a ligand that forms an affinity complex with an effector-FFSH particle of the invention, and those molecules or cells that do not have such a ligand.

Abstract: A process for magnetic immunoseparation of cells, in particular bacteria, fetal cells, stock cells of bone marrow and circulating cancerous cells, of the type consisting in affixing the target cells on paramagnetic balls and in causing a magnetic field to act on a sample containing the affixed cells, the free cells and the surplus paramagnetic balls, in order to isolate the paramagnetic balls, in that the sample is caused to circulate in a tube the section of which is much less than the length over which the magnetic field is applied.

Abstract: Disclosed is a high throughput compatible assay that is useful for the identification of specific antagonists of TRAF-receptor interactions. The modular flexibility of the assay makes it possible to introduce simple modifications in order to measure the interaction of any TNF receptor cytoplasmic domain (or TRAF-binding protein) with any of the six TRAF proteins, TRAF1, TRAF2, TRAF3, TRAF4, TRAF5 and TRAF6.

Abstract: This invention provides methods an apparatus for detecting and quantifying particulate matter suspended in a fluid. Specifically, the invention provides an integrated, affinity-binding based, analytical system comprising a platform for performing an affinity-binding based assay for specifically binding particulates including microbial cells, and a detection means for detecting the particulates specifically bound to a defined surface or chamber comprising the platform. Methods for using the analytical systems of the invention are also provided.

Abstract: The superparamagnetic monodispersed particles comprise a core of a first polymer, an internal layer of a second polymer coating the core and in which a magnetic material is distributed, and an external layer of a third polymer coating the magnetic layer and capable of interacting with at least one biological molecule. At least the second polymer is heat sensitive and has a predetermined lower critical solubility temperature (LCST) of 15-65.degree. C. These particles may be used to isolate at least one biological molecule from a liquid specimen.

Abstract: A biosensor apparatus for detecting a binding event between a ligand and receptor. The apparatus includes an electrode substrate coated with a high-dielectric hydrocarbon-chain monolayer, and having ligands attached to the exposed monolayer surface. Binding of a receptor to the monolayer-bound ligand, and the resultant perturbation of the monolayer structure, causes ion-mediated electron flow across the monolayer. In one embodiment, the monolayers have a coil-coil heterodimer embedded therein, one subunit of which is attached to the substrate, and the second of which carries the ligand at the monolayer surface.

Abstract: The slope lines of the peak lines are determined for a reference specimen and a test specimen and then compared with one another to analyze peak lines independently of the background. Preferably a minimum amplitude of a slope line is established with a threshold specimen so that fluctuations with a smaller amplitude can be disregarded. This method is suitable especially for automatic analysis of blot strips.

Abstract: An apparatus for the qualitative and/or quantitative measurement of analytes, in particular in biological samples by means of receptor ligand binding and having a magnetizing device for the production of a magnetic field at the location of the sample and with a detection device for measurement of magnetic properties of the sample is characterized in that the magnetizing device is spatially disposed with respect to the detection device in such a fashion that the magnetic field produced by the magnetization device at the location of the magnetization is attenuated by at least a factor of 10, and preferentially by a factor of 1000 or more, at the location occupied by the sample during the measurement, or in that a switching device is provided for which, throughout a predetermined time duration and in particular during the measurement phase of the detection device can switch-off the magnetic field of the magnetizing device at the location of the sample.

Abstract: An arrangement for the investigation of hydrophilic macromolecules (1) in an aqueous solution having a solid carrier surface (5) onto which a lipid film (24) is disposed, wherein the molecules (1) to be investigated are bound, by means of a molecular coupling system (20), to the lipid film (24) and thus are immobilized, is characterized in that the molecular coupling system (20) comprises at least two, preferably three molecular or nuclear components (21, 22, 23), which can be coupled to each other, of which a first component (21) is bound to the lipid film (24) and a second component (22) is bound to a hydrophilic macromolecule (1) to be investigated. In this way, it is rendered possible to immobilize and investigate any hydrophilic macromolecules, wherein the coating of the solid carrier surface should be able to be carried out in an as easy as possible and reversible manner.

Abstract: A lysis chamber of an assay device capable of producing lysis of cells in a sample fluid such as whole blood, said chamber comprising a surface which contacts the sample fluid when the sample fluid is placed into the assay device; and a lytic material immobilized on the surface, whereby cells of the sample fluid are lysed when they contact the lytic material. The chamber can delimit a capillary space, and lytic material can be saponin or a detergent. Methods employing devices comprising such chambers can assay for whole blood amounts of cyclosporin or hemoglobin A1c.

Abstract: A compact combination blood cell count and immunoassay apparatus for measuring drawn whole blood specimen includes a load station for receiving the whole blood specimen and a nozzle member that can selectively withdraw whole blood from the blood specimen. A blood cell count section and an immunoassay section are mounted along a unitary path of movement of the nozzle member so that a single nozzle member may be used for transporting the whole blood to the respective blood cell count section and immunoassay section. A controller can automatically direct a transport mechanism to use only the whole blood and to perform various steps of adding dilution liquid and reagents, along with appropriate washing of the nozzle and sample cells to insure an automatic operation. A hematozorit value can be determined from the blood cell count signal and used to correct the immunoassay signal when whole blood is used.

Abstract: An automatic immunoassay method and apparatus which not only permit automatic operations of supplying and discarding reaction tubes, washing for B/F separation, dispensation of reagents, and measurement, but also permit the reaction time to be varied arbitrarily and can cope with any of the assay techniques including one-step and two-step noncompetitive sandwich techniques and competitive techniques.

Abstract: The present invention provides internally calibrated competitive assays for use on a solid support. Additionally, the invention provides a method of using such assays.

Abstract: The test kit includes a substrate and, welded or bonded thereto, a plastic sheet having blisters. One of the blisters is shaped as a siphon. The other blisters act as reaction vessels and also serve to receive and store a reagent. The test kit may contain a test strip in one of the blisters. The test kit is particularly suited for carrying out immunological tests, whereby the siphon markedly facilitates the procedure during the washing step.

Abstract: A non-competitive method for the determination of analytes. Initially the analyte is bound to a specific binding partner, after which the unoccupied binding sites of the binding partner are inactivated. The bound analyte is then dissociated from the binding partner and replaced by a labeled marker, after which the bound labeled marker is determined. The signal from the bound labeled marker is directly proportional to the initial amount of analyte in the sample, which makes the present method more favorable than the competitive assays.

Abstract: The invention relates to a method for separating magnetic particles from a composition in a vessel. In the method, particles are first concentrated on the wall of the vessel and collected from this area by using a separation means (1) to which the magnetic particles adhere. In this way, particles can be collected efficiently. The invention can be used in different applications especially in the fields of biotechnology, biochemistry, and biomedicine.

Abstract: Improvements in the existing procedures and materials for conduct of high gradient magnetic separation (HGMS) are disclosed. The use of plastic coated matrices especially small spheres or balls which form superior magnetic gradient-intensifying supports are disclosed, along with improved methods and apparatus to conduct HGMS. The selection of small spheres in combination with the coating provides for uniform matrices of high stability.

Abstract: A method for the assessment of bone fragility and osteoporosis fracture risk characterized by:measuring in vitro the concentration of under-carboxylated osteocalcin in a biological fluid sample such as serum, plasma or urine;comparing the concentration of under-carboxylated osteocalcin in the test sample with the concentration in a control sample containing levels of under-carboxylated osteocalcin representative of the upper limit of the normal range, concentrations above this upper limit being indicative of increased risk of bone fracture.