Abstract: An analytical system comprises a frame and movable carriage. An analytical rotor is mounted on the carriage and can be translated among a sample dispensing station, a fluid dispensing station, and a label detection zone. In order to perform assays, the analyzer system requires only the introduction of the analytical rotor, sample, and a volume of diluent solution. Sample within the analyzer is contained at all times within either a sample receptacle or the rotor. The method allows for the sequential addition of sample and diluent in order to perform multiple assay steps and is particularly suitable for performing heterogeneous immunoassays. The use of fluorescent label in the system allows multiple analyte detection reactions to be performed from a single sample applied to a single rotor.

Abstract: A system for separating plasma from whole blood comprises a blood separation device and a blood separation driver. The blood separation device includes a flexible tube having a needle and shield at one end and a filter member at the other end. The needle may be used to access blood in a conventional blood collection device. The separation driver applies a peristaltic force to the flexible tube of the blood separation device, thus drawing blood from the collection device through the tube and to the filter member. The driver also includes a frame having a collar and clamp mechanism for supporting the inlet end of the flexible tube, thus allowing use of the blood driver without directly exposing it to the blood. Plasma may be collected from the filter element. The present invention also provides blood dispensing systems and methods for dispensing whole and pre-filtered blood. Such blood dispensing systems comprise a blood dispensing device and a blood dispensing driver.

Abstract: A system for separating plasma from whole blood comprises a blood separation device and a blood separation driver. The blood separation device includes a flexible tube having a needle and shield at one end and a filter member at the other end. The needle may be used to access blood in a conventional blood collection device. The separation driver applies a peristaltic force to the flexible tube of the blood separation device, thus drawing blood from the collection device through the tube and to the filter member. Plasma may be collected from the filter element.

Abstract: The system for transferring plasma to a test substrate comprises an applicator and the test substrate. The applicator includes a blood reservoir and a filter element which separates cellular components from the blood as plasma is passed to the test substrate. The test substrate includes an absorptive element which receives the plasma from the applicator. In one embodiment, measured amounts of plasma are transferred when the absorptive element becomes saturated, thus stopping the flow of plasma. In another embodiment, excess blood and cellular components are removed from the measured plasma by disengaging the applicator from the test substrate. In another embodiment, plasma transferred to the absorptive element is eluted from the absorptive element by subsequent application of an elution medium.

Abstract: A system is disclosed for measuring immunofluorescence of a thin sample layer mounted on a substrate. A sample is located in a radiation beam having a spacially-varying amplitude, for example a series of nodes and antinodes. The sample layer is small to comparison to the period over which the radiation intensity varies, but the support is large in comparison to the period. Thus, when the sample and support are moved relative to the radiation beam, the fluorescence signal from the sample layer will be significantly affected, while the signal from the support is substantially unaffected. The difference between two measurements at different relative orientations of the source and radiation beam can provide a measure of the fluorescence of the sample layer independent of any background scatter of fluorescence of the support.

Abstract: A fluorescent labelling composition comprises a linear polysaccharide backbone molecule having a plurality of target-binding molecules, such as antibodies or nucleic acids, attached at spaced-apart intervals thereon. Each of the target-binding molecules, in turn, includes a multiplicity of fluorescent dye molecules bound thereto. In this way, fluorescent signal introduced to a single target-site on a solid phase surface may be increased without loss of binding activity.

Abstract: The system for transferring plasma to a test substrate comprises an applicator and the test substrate. The applicator includes a blood reservoir and a filter element which separates cellular components from the blood as plasma is passed to the test substrate. The test substrate includes an absorptive element which receives the plasma from the applicator. In one embodiment, measured amounts of plasma are transferred when the absorptive element becomes saturated, thus stopping the flow of plasma. In another embodiment, excess blood and cellular components are removed from the measured plasma by disengaging the applicator from the test substrate. In another embodiment, plasma transferred to the absorptive element is eluted from the absorptive element by subsequent application of an elution medium.

Abstract: A solid-phase binding assay that measures interferometrically either antibodies or binding pair antigens bound to a spinning disc on which the complementary antigen or antibody has previously been coated in an alternating pattern of immunologically active and inactive spots. The spinning disc is inserted into one arm of a Mach-Zehnder interferometer and as the disc spins the bound and unbound spots pass one after another through the two light beams causing a periodic phase shift in the light. These phase modulated light beams are then recombined at a beam-splitter converting the phase modulation into an amplitude modulation. The two recombined beams then fall on a photodetector which converts the periodically varying optical power into a periodically varying electrical current whose amplitude is proportional to the amount of bound protein on the surface of the disc and whose modulation frequency is equal to the frequency with which the spots pass through the light beam.