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: A method is described for removing residue from a fluid deposited on the interior surface of an inkjet printhead after the printhead has contained or dispensed the fluid at least once. The method makes use of a reverse flushing technique optionally used in combination with sonication. A cleaning station for flushing an inkjet printhead with a wash fluid, rinse fluid, and/or inert gas is provided as well.

Abstract: Methods and compositions are provided for producing arrays of polymeric binding agents. In the subject methods, the individual polymers of the array are synthesized using solid phase synthesis techniques on the surface of a substrate. A critical feature of the invention is that one or more locations on the substrate surface are spatially and temporally protected by a protective bubble during the synthesis protocol, where the protective bubble may be produced using any convenient bubble producing means. The bubble producing means may be a component of either a substrate or a structure separate from the substrate. Also provided are the arrays produced by the subject methods, kits for use in practicing the subject methods, and methods of using the arrays in analyte detection assays, including hybridization assays, such as gene discovery, differential gene expression and gene sequencing assays.

Abstract: A method of testing multiple fluid samples with multiple biopolymer arrays. A cover is assembled to a contiguous substrate carrying on a first side, multiple arrays each with multiple regions of biopolymers linked to the substrate, such that the cover and the substrate together form a plurality of chambers each containing a biopolymer array and each being accessible through its own port. Multiple fluid samples are introduced into respective chambers through a port of each such that the fluid samples contact respective arrays. A binding pattern of the arrays is observed. An apparatus and kit useful in such methods, are also provided.

Abstract: A method and apparatus for fabricating an array of biopolymers on a substrate using a biopolymer or biomonomer fluid, and using a dispensing head. The head has a reservoir chamber and at least one jet which can dispense droplets onto a substrate. The jet includes a capillary delivery chamber communicating with the reservoir chamber, which delivery chamber has an orifice. The jet further includes an ejector which, when activated, causes a droplet to be ejected from the orifice. The method includes loading the head by positioning the head with the orifice adjacent and facing a biomonomer or biopolymer fluid, and providing a load pressure to the reservoir chamber. The load pressure is sufficiently negative such that the fluid is drawn into the reservoir chamber through the orifice and delivery chamber, while simultaneously being insufficient to result in ambient atmosphere entering the delivery chamber through the orifice once the head has been loaded and no further fluid is facing and adjacent the orifice.

Abstract: An apparatus, systems and methods use an r, &thgr; format for the manufacture and analysis of biological materials. The apparatus is an array of discrete features of biological material in an annular region on a substrate. The apparatus is formed with a system for synthesizing arrays that includes a spinner assembly for rotating the substrate during the synthesis of the biological material thereon. The spinner assembly provides efficient means for printing an annular array pattern, spreading and removing ancillary fluids used in the synthesis process. The apparatus is hybridized with complementary biological material using a system for hybridizing that includes a spinner assembly to spin the apparatus after the complementary biological material is added. The spinning motion spreads the complementary biological material efficiently over the annular array such that a much smaller amount of complementary biological material is needed for the assay.

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: A method and apparatus for fabricating an array of biopolymers on a substrate using a biopolymer or biomonomer fluid, and using a fluid dispensing head. The head has at least one jet which can dispense droplets onto a substrate, the jet including a chamber with an orifice, and including an ejector which, when activated, causes a droplet to be ejected from the orifice. The method includes positioning the head with the orifice facing the substrate. Multiple droplets of the biopolymer or biomonomer fluid are dispensed from the head orifice so as to form an array of droplets on the substrate. A gas flow is directed through a venturi which has a throat opening communicating with the dispensing head chamber. A venturi control valve which particularly communicate with an outlet of the venturi, is adjusted to alter the chamber pressure. The venturi may be driven by a source of inert anhydrous compressed gas which assists in maintaining fluid in the head isolated from moisture.

Abstract: Methods and compositions are provided for producing arrays of polymeric binding agents. In the subject methods, the individual polymers of the array are synthesized using solid phase synthesis techniques on the surface of a substrate. A critical feature of the invention is that one or more locations on the substrate surface are spatially and temporally protected by a protective bubble during the synthesis protocol, where the protective bubble may be produced using any convenient bubble producing means. The bubble producing means may be a component of either a substrate or a structure separate from the substrate. Also provided are the arrays produced by the subject methods, kits for use in practicing the subject methods, and methods of using the arrays in analyte detection assays, including hybridization assays, such as gene discovery, differential gene expression and gene sequencing assays.

Abstract: The invention provides an apparatus and method for conducting chemical or biochemical reactions on a solid surface within an enclosed chamber. The invention may be used in conducting hybridization reactions, as of biopolymers such as DNA, RNA, oligonucleotides, peptides, polypeptides, proteins, antibodies, and the like. In another aspect, the invention provides an improved method for mixing a thin film of solution, as in a hybridization chamber. The invention further provides a kit for carrying out the methods of the invention.

Abstract: Apparatus for delivering a plurality of different biological materials onto discrete locations on a receiving surface, as for example to fabricate an array of different biological materials, includes a plurality of orifices in an orifice member, at least six delivery chambers each in fluid conducting relationship with at least one of the orifices, a plurality of reservoirs each in fluid communication with at least one of the delivery chambers, means associated with each orifice for propelling fluid through the associated orifice from the delivery chamber that is in fluid conducting relationship with the orifice, and a vent for commonly venting at least two of the reservoirs. In some embodiments the chambers and reservoirs are loaded with fluids containing selected biomolecules by drawing the selected fluids into the chambers through the orifices; in other embodiments the fluids are introduced into the reservoirs.

Abstract: Array hybridization devices and methods for their use are provided. The subject devices are characterized by having a substantially planar bottom surface, a cover, at least one fluid port and at least one adjustable spacing element for adjusting the spacing between an array and the bottom surface. In using the subject devices, an array is placed on the at least one adjustable spacing element in the chamber and the space between the array and the bottom surface is adjusted by moving the at least one adjustable spacing element. The adjusted array is contacted with at least one biological sample introduced into the chamber. The subject inventions find use in a variety of array-based applications, including nucleic acid array hybridizations.

Abstract: A method and apparatus for fabricating an array of biopolymers on a substrate using a biopolymer or biomonomer fluid, and using a dispensing head. The head has a reservoir chamber and at least one jet which can dispense droplets onto a substrate. The jet includes a capillary delivery chamber communicating with the reservoir chamber, which delivery chamber has an orifice. The jet further includes an ejector which, when activated, causes a droplet to be ejected from the orifice. The method includes loading the head by positioning the head with the orifice adjacent and facing a biomonomer or biopolymer fluid, and providing a load pressure to the reservoir chamber. The load pressure is sufficiently negative such that the fluid is drawn into the reservoir chamber through the orifice and delivery chamber, while simultaneously being insufficient to result in ambient atmosphere entering the delivery chamber through the orifice once the head has been loaded and no further fluid is facing and adjacent the orifice.

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: A method and apparatus for fabricating an array of biopolymers on a substrate using a biopolymer or biomonomer fluid, and using a fluid dispensing head. The head has at least one jet which can dispense droplets onto a substrate, the jet including a chamber with an orifice, and including an ejector which, when activated, causes a droplet to be ejected from the orifice. The method includes positioning the head with the orifice facing the substrate. Multiple droplets of the biopolymer or biomonomer fluid are dispensed from the head orifice so as to form an array of droplets on the substrate. A gas flow is directed through a venturi which has a throat opening communicating with the dispensing head chamber. A venturi control valve which particularly communicate with an outlet of the venturi, is adjusted to alter the chamber pressure. The venturi may be driven by a source of inert anhydrous compressed gas which assists in maintaining fluid in the head isolated from moisture.

Abstract: An adjustable-volume, sealed chemical-solution-confinement vessel for enclosing the inner bottom surface of the chemical-solution-confinement vessel within a sealed chamber. The chemical-solution-confinement vessel comprises a well-shaped base into which a complementarily-shaped lid is inserted. The lid can be inserted to a first position, in order to create a small volume sealed chamber above the inner bottom surface of the chemical-solution-confinement vessel, and can be retracted to a second position in order to create a larger volume sealed chamber above the inner bottom surface of the chemical-solution-confinement vessel. The lid may contain a port or aperture for introducing a fluid or material into the sealed chamber.

Abstract: The invention provides an apparatus and method for conducting chemical or biochemical reactions on a solid surface within an enclosed chamber. The invention may be used in conducting hybridization reactions, as of biopolymers such as DNA, RNA, oligonucleotides, peptides, polypeptides, proteins, antibodies, and the like. In another aspect, the invention provides an improved method for mixing a thin film of solution, as in a hybridization chamber. The invention further provides a kit for carrying out the methods of the invention.

Abstract: A method and apparatus for fabricating an array of biopolymers on a substrate using a biopolymer or biomonomer fluid, and using a fluid dispensing head. The head has at least one jet which can dispense droplets onto a substrate, the jet including a chamber with an orifice, and including an ejector which, when activated, causes a droplet to be ejected from the orifice. The method includes positioning the head with the orifice facing the substrate. Multiple droplets of the biopolymer or biomonomer fluid are dispensed from the head orifice so as to form an array of droplets on the substrate. A gas flow is directed through a venturi which has a throat opening communicating with the dispensing head chamber. A venturi control valve which particularly communicate with an outlet of the venturi, is adjusted to alter the chamber pressure. The venturi may be driven by a source of inert anhydrous compressed gas which assists in maintaining fluid in the head isolated from moisture.

Abstract: The present invention provides centrifugal rotors for delivering a premeasured volume of liquid to a chamber in the rotor. In particular the rotors include siphons for delivering a premeasured volume of liquid between a first and a second chamber in the rotor. The siphons of the invention are designed such that the inlet of the siphon on the first chamber is radially outward of the siphon outlet on the second chamber. The first chamber is emptied to a level equivalent to the radial position of the siphon outlet.

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.