Abstract: Methods and devices are provided for analyzing acetone in breath. One such method comprises disposing a reactant in a reaction zone within the breath analysis device, wherein the reactant comprises a primary amine disposed on a surface, and wherein the reaction zone has an optical characteristic that is at a reference level. It also comprises pre-storing a liquid nitroprusside solution within the breath analysis device separately from the reactant. The method further comprises using the breath analysis device to cause the breath to contact the reactant in the reaction zone so that the acetone in the breath reacts with the reactant to form a reaction product and, after the reaction product has been formed, using the breath analysis device to cause the nitroprusside solution to contact and react with the reaction product and to facilitate a change in the optical characteristic of the reaction zone relative to the reference level.

Abstract: Methods and devices are provided for analyzing acetone in breath. One such method comprises disposing a reactant in a reaction zone within the breath analysis device, wherein the reactant comprises a primary amine disposed on a surface, and wherein the reaction zone has an optical characteristic that is at a reference level. It also comprises pre-storing a liquid nitroprusside solution within the breath analysis device separately from the reactant. The method further comprises using the breath analysis device to cause the breath to contact the reactant in the reaction zone so that the acetone in the breath reacts with the reactant to form a reaction product and, after the reaction product has been formed, using the breath analysis device to cause the nitroprusside solution to contact and react with the reaction product and to facilitate a change in the optical characteristic of the reaction zone relative to the reference level.

Abstract: Methods and devices are provided for analyzing acetone in breath. One such method comprises disposing a reactant in a reaction zone within the breath analysis device, wherein the reactant comprises a primary amine disposed on a surface, and wherein the reaction zone has an optical characteristic that is at a reference level. It also comprises pre-storing a liquid nitroprusside solution within the breath analysis device separately from the reactant. The method further comprises using the breath analysis device to cause the breath to contact the reactant in the reaction zone so that the acetone in the breath reacts with the reactant to form a reaction product and, after the reaction product has been formed, using the breath analysis device to cause the nitroprusside solution to contact and react with the reaction product and to facilitate a change in the optical characteristic of the reaction zone relative to the reference level.

Abstract: Disclosed are compositions and a method relating to amplifying and detecting nucleic acids.

Abstract: Methods and devices are provided for analyzing acetone in breath. One such method comprises disposing a reactant in a reaction zone within the breath analysis device, wherein the reactant comprises a primary amine disposed on a surface, and wherein the reaction zone has an optical characteristic that is at a reference level. It also comprises pre-storing a liquid nitroprusside solution within the breath analysis device separately from the reactant. The method further comprises using the breath analysis device to cause the breath to contact the reactant in the reaction zone so that the acetone in the breath reacts with the reactant to form a reaction product and, after the reaction product has been formed, using the breath analysis device to cause the nitroprusside solution to contact and react with the reaction product and to facilitate a change in the optical characteristic of the reaction zone relative to the reference level.

Abstract: Various systems and devices are disclosed for measuring an analyte, such as acetone, in a breath sample of a human subject. In some embodiments, a system is provided that includes a displosable cartridge having a reaction chamber containing an interactant, such as interactant particles. The interactant reacts with an analyte in a breath sample that is passed along a flow path through the reaction chamber. An optical subsystem measures a color change resulting from a reaction in the reaction chamber; this color change is indicative of a concentration of the analyte in the breath sample. In some embodiments, the optical subsystem illuminates the cartridge using multiple LEDs of different colors or wavelengths.

Abstract: Methods and devices are provided for analyzing acetone in breath. One such method comprises disposing a reactant in a reaction zone within the breath analysis device, wherein the reactant comprises a primary amine disposed on a surface, and wherein the reaction zone has an optical characteristic that is at a reference level. It also comprises pre-storing a liquid nitroprusside solution within the breath analysis device separately from the reactant. The method further comprises using the breath analysis device to cause the breath to contact the reactant in the reaction zone so that the acetone in the breath reacts with the reactant to form a reaction product and, after the reaction product has been formed, using the breath analysis device to cause the nitroprusside solution to contact and react with the reaction product and to facilitate a change in the optical characteristic of the reaction zone relative to the reference level.

Abstract: Disclosed are compositions and a method relating to amplifying and detecting nucleic acids.

Abstract: Disclosed are compositions and a method relating to amplifying and detecting nucleic acids.

Abstract: Disclosed are methods, rapid probes, and kits for general purpose nucleic acid detection.

Abstract: Disclosed are compositions and a method relating to amplifying and detecting nucleic acids.

Abstract: A method of determining the concentration of an analyte of interest in breath. The method includes obtaining a disposable cartridge comprising a reaction chamber, a liquid chamber, and a window to permit determination of a color intensity in the reaction chamber, directing a volume of breath into the cartridge, and initiating a sequence whereby liquid is released from the liquid container into the reaction chamber to cause a reaction which produces a change in the intensity of a color viewable through the window. The intensity of the color corresponds to the concentration of the analyte of interest. The reaction progresses through a kinetic phase and eventually reaches equilibrium. The sequence additionally includes measuring the intensity of the color at a point in the kinetic phase, to determine the concentration of the analyte of interest in breath.

Abstract: Methods and devices are provided for analyzing acetone in breath. One such method comprises disposing a reactant in a reaction zone within the breath analysis device, wherein the reactant comprises a primary amine disposed on a surface, and wherein the reaction zone has an optical characteristic that is at a reference level. It also comprises pre-storing a liquid nitroprusside solution within the breath analysis device separately from the reactant. The method further comprises using the breath analysis device to cause the breath to contact the reactant in the reaction zone so that the acetone in the breath reacts with the reactant to form a reaction product and, after the reaction product has been formed, using the breath analysis device to cause the nitroprusside solution to contact and react with the reaction product and to facilitate a change in the optical characteristic of the reaction zone relative to the reference level.

Abstract: A method for extending an effective working range of an analyzer for measuring an analyte in a breath sample. The method includes initiating a reaction in the analyzer that produces an optically discernable reaction product having an optical property that is indicative of a concentration of the analyte in the breath sample, taking a first reading of the optical property at a first time, and comparing the first reading to a reference. If the comparison yields a first state, the method includes determining the concentration using the first reading. If it yields a second state different from the first state, the method includes taking a second reading of the optical property at a second time, and determining the concentration of the analyte using the second reading. Other methods are provided as well.

Abstract: A method for extending an effective working range of an analyzer for measuring an analyte in a breath sample. The method includes initiating a reaction in the analyzer that produces an optically discernable reaction product having an optical property that is indicative of a concentration of the analyte in the breath sample, taking a first reading of the optical property at a first time, and comparing the first reading to a reference. If the comparison yields a first state, the method includes determining the concentration using the first reading. If it yields a second state different from the first state, the method includes taking a second reading of the optical property at a second time, and determining the concentration of the analyte using the second reading. Other methods are provided as well.

Abstract: A disposable cartridge is provided for indicating the concentration of an analyte of interest in breath. The cartridge includes a housing having a side wall and a longitudinal axis, a reaction chamber in the housing, an optically transparent window in the side wall, for viewing contents of the reaction chamber, the window having a height measured in the direction of the longitudinal axis, and a liquid chamber in the housing. The cartridge is configured to display a color that extends along the entire height of the window following the transfer of liquid from the liquid chamber into the reaction chamber. The intensity of the color corresponds to a concentration of the analyte of interest in the reaction chamber.

Abstract: A method of determining the concentration of an analyte of interest in breath. The method includes obtaining a disposable cartridge comprising a reaction chamber, a liquid chamber, and a window to permit determination of a color intensity in the reaction chamber, directing a volume of breath into the cartridge, and initiating a sequence whereby liquid is released from the liquid container into the reaction chamber to cause a reaction which produces a change in the intensity of a color viewable through the window. The intensity of the color corresponds to the concentration of the analyte of interest. The reaction progresses through a kinetic phase and eventually reaches equilibrium. The sequence additionally includes measuring the intensity of the color at a point in the kinetic phase, to determine the concentration of the analyte of interest in breath.

Abstract: An analyzer is provided for sensing an analyte in breath of a patient. The analyzer includes a base, a breath input port on the base for removable coupling to a source of breath, a cartridge receiving cavity on the base for removably receiving a disposable cartridge having an optically transparent window and a reaction volume, a flow path in the base configured to place the breath input port into communication with the reaction volume when the cartridge is installed in the cartridge receiving cavity, an optical subsystem in the base that senses an optical change in the reaction volume through the window, and a pump in the base configured to pump breath from the source of breath to the reaction volume during a measurement cycle when the source of breath is coupled to the breath input port, and to pump atmospheric air through the flow path during a flush cycle.

Abstract: Disclosed herein are methods of nucleic acid amplification, including methods of preventing non-specific reaction of a nucleotide sequence with a DNA modifying enzyme.

Abstract: Disclosed are methods and compositions related to real-time PCR and other nucleic acid extension or amplification reactions.