Abstract: A method and apparatus is provided for mixing a film of fluid, particularly a film of chemical, biochemical, or biological fluids undergoing a reaction. The apparatus comprises a means for nucleating a bubble using a discrete heat source, such as a resistor, and moving the bubble in the fluid by creating a temperature gradient, thereby mixing the fluid.

Abstract: The invention relates to a method and an apparatus for performing an assay on chemical, biochemical, or biological fluids. The apparatus includes an assay chamber for fluid reactions and a centrifugal force activated-valve for controlling fluid movement through the assay chamber. An active surface can be positioned in the assay chamber to react with fluids passed through the assay chamber. The active surface may contain biomolecular probes. The biomolecular probes can be DNA, DNA fragments, RNA, RNA fragments, reagents, protein, protein fragments, lipids, and lipid fragments. The apparatus is particularly useful when multiple reactions, dilutions, or washing steps are required to determine a final answer. The centrifugal force activated-valve provides positive control over fluid in the assay chamber and allows for repeated use of the same chamber for multiple reaction steps. The apparatus can be disposed of after an assay to eliminate potential contamination from reuse of the same apparatus.

Abstract: The invention relates to a method and apparatus for mixing thin films of fluid, particularly thin films of chemical, biochemical, or biological fluids undergoing reactions. The invention employs a mixing mechanism which induces mixing within the fluid chamber by moving the inner face of at least one surface of the fluid chamber relative to the inner face of another surface of the fluid chamber, thus enhancing the sensitivity or specificity of the reaction, rate of reaction, extent of reaction, homogeneity, or percentage yield. The invention is particularly useful in enhancing the results of chemical and biological assays.

Abstract: A technique for analyzing target chemicals is provided. The apparatus of the technique contains an array of two or more light sources. Each of the array elements includes a light source. The light source has an emitting surface from which light can be emitted. Two or more binder chemical moieties are associated with the light sources at the emitting surfaces. These binder chemical moieties can bind target chemicals such that different target chemicals can be bound to the array. Light emitted by the light sources impinges on target chemicals bound to the light sources and will cause light interaction (e.g., fluorescence) with the target chemicals to result in a light pattern or patterns to indicate the presence or quantity of the target chemicals. The array is formed by a tiling technique involving the arrangement of tiles of array elements in a desired pattern.

Abstract: The present invention provides an analytical rotor which holds a fluid in a chamber, typically to allow mixing with a reagent, and transfers the fluid to a receiving chamber in the rotor. The rotor comprises a holding chamber having an single exit duct and a receiving chamber connected to the holding chamber through the exit duct. The exit duct prevents flow at a first rotational speed and allows flow at a second, higher rotational speed. The exit duct may include a capillary passage in which capillary forces prevent flow until the rotational speed is increased. Alternatively, the exit duct may include a siphon.

Abstract: The present invention provides lyophilized reagent spheres comprising reagents suitable for analysis of biological samples, in particular analysis of blood samples in centrifugal analyzers. Also provided are diluents which are conveniently used in such analyzers.

Abstract: The present invention provides centrifugal rotors for delivering a liquid, typically a biological sample such as diluted plasma, to an unvented chamber in the rotor through an unmodified inlet channel. The unvented chamber is typically a cuvette comprising reagents necessary for analysis of a biological sample. The unmodified inlet channels are sized such that, as the rotor spins, gas escapes from the chamber through the inlet channel as the liquid enters the chamber through the inlet channel. The primary feature which allows the air to escape from the unvented chamber is that the cross sectional area of the inlet channel is greater than the cross sectional area of the liquid flowing through it.

Abstract: The present invention provides an analytical rotor which holds a fluid in a chamber, typically to allow mixing with a reagent, and transfers the fluid to a receiving chamber in the rotor. The rotor comprises a holding chamber having an single exit duct and a receiving chamber connected to the holding chamber through the exit duct. The exit duct prevents flow at a first rotational speed and allows flow at a second, higher rotational speed. The exit duct may include a capillary passage in which capillary forces prevent flow until the rotational speed is increased. Alternatively, the exit duct may include a siphon.

Abstract: An analytical rotor which comprises a receptacle for receiving a post on a centrifuge and means in the rotor body proximate to the receptacle for releasing a liquid in response to mounting the rotor in the centrifuge is disclosed. The means for releasing the liquid is preferably a sealed container shiftably positioned in a chamber proximate the receptacle.

Abstract: An analytical rotor which comprises a receptacle for receiving a post on a centrifuge and a sealed rigid container in the rotor body proximate to the receptacle is provided. The seal on the container is opened when the post is inserted in the receptacle, thereby releasing a liquid in the container. The seal is preferably opened through the displacement of the container caused by positioning of the rotor on the centrifuge post.

Abstract: An analytical rotor for separating plasma whole blood comprises a rotor body having a sample application port in an upper surface thereof. Blood introduced to the sample application port is metered into a metering chamber by capillary flow while the rotor remains stationary. Excess blood passes into an overflow chamber by capillary flow, either simultaneously with the metered flow or after opening of a vent in the overflow chamber. Subsequent rotation of the rotor causes metered blood in the metering chamber to flow into a receiving chamber, typically a plasma separation chamber.

Abstract: An analytical rotor for separating cellular components from a biological fluid includes a separation chamber spaced radially outward from a sample chamber. The sample chamber may be an open receptacle disposed to receive sample or may be a mixing chamber which receives sample and diluent. A flow restrictive channel connects the sample chamber to the separation chamber so that fluid enters the separation chamber at a controlled rate. The cellular components collect within a retention region located generally at the outer periphery of the collection chamber while cell-free fluid is continuously removed through a collection port. The collection port is spaced annularly apart from the flow channel so that there is sufficient residence time within the separation chamber for substantially complete separation of the cells from the fluid fraction.

Abstract: The present invention provides a centrifugal rotor which measures and delivers a predetermined volume of fluid to a receiving chamber in the rotor. The rotor comprises a bulk fluid chamber containing a bulk amount of fluid and a metering chamber which has a predetermined volume. The bulk fluid flowing into the metering chamber fills the chamber and excess fluid flows out into an overflow chamber. Thus, a predetermined volume is obtained. This volume is delivered to the receiving chamber through an exit duct which prevents flow at the rotational speed required to fill the metering chamber but allows flow at a second, higher rotational speed. The exit duct is typically a capillary in which capillary forces prevent flow until the rotational speed is increased.