Provided are an amadoriase that is less likely to be influenced by oxygen concentration and a method and a reagent kit for measurement of HbA1c using such amadoriase. Provided are an amadoriase that is obtained via substitution of one or more amino acid residues at a position or positions corresponding to the position(s) selected from the group consisting of positions 280, 267, 269, 54, and 241 of the amadoriase derived from the genus Coniochaeta, a method for measurement of HbA1c, a reagent kit for measurement, and a sensor using such amadoriase. The modified amadoriase according to the invention has a lowered oxidase activity and an enhanced dehydrogenase activity, and this enables the use of an electron mediator, and this reduces the influence of oxygen concentration. Thus, HbA1c can be measured with high sensitivity.

A reagent for detecting an analyte comprises a flavoprotein enzyme, a mediator such as a phenothiazine mediator, at least one surfactant, a polymer and a buffer. The reagent may be used with an electrochemical test sensor that includes a plurality of electrodes.

This invention provides methods for predicting response to anti-TNFα biological agent treatment in a rheumatoid arthritis patient and methods for selecting a treatment for a rheumatoid arthritis patient, the methods comprising determining the level of expression of PIK3CD as a biomarker, and optionally also determining the level of expression of CX3CL1 as a second biomarker. The invention additionally provides kits for carrying out the methods described.

The present invention provides sensor cells comprising a receptor that binds to an analyte indicative of the presence of an agent, where binding of the analyte to the receptor triggers a detection event that is indicative of the presence of the agent. In certain embodiments, the detection event is appearance of a reporter detectable by the naked eye. The present invention also provides uses of such sensor cells for detecting the presence of an agent in a sample.

The invention provides amperometric analyte sensor systems comprising one or more electrodes designed to monitor in vivo levels of 3-hydroxybutyrate (and optionally glucose as well) in order to facilitate the management of diabetic ketoacidosis. The invention further includes dual layer membrane compositions, elements and methods useful with such amperometric analyte sensor systems.

A working electrode measuring the presence of an analyte is described as one embodiment. The working electrode includes a working conductor with a reactive surface that is operated at a first potential. The working electrode further includes a first transport material with properties that enable analyte flux to the reactive surface. Additionally, the working electrode has a second transport material with properties that enable reactant flux to the reactive surface, wherein the analyte flux and the reactant flux are in dissimilar directions.

A method of calibrating a device for measuring the concentration of creatinine using one or more calibration solutions, the method comprising: receiving concentrations at an initial time of creatine, Cr, and/or creatinine, Crn, of the one or more calibration solutions; receiving outputs of the measuring device at the end time; calculating the concentration of Cr and/or Crn in the calibration solutions at an end time using a temperature model, wherein the temperature model indicates an estimation of the temperature of the calibration solutions from the initial time to the end time, and wherein the temperature model includes a variable parameter; and determining a relationship between the outputs of the measuring device and the calculated concentrations of Cr and/or Crn.

NADP-dependent oxidoreductase compositions, and electrodes, sensors and systems that include the same. Analyte sensors include an electrode having a sensing layer disposed thereon, the sensing layer comprising a polymer and an enzyme composition distributed therein. The enzyme composition includes nicotinamide adenine dinucleotide phosphate (NAD(P).sup.+) or derivative thereof; an NAD(P).sup.+-dependent dehydrogenase; an NAD(P)H oxidoreductase; and an electron transfer agent comprising a transition metal complex.

The present disclosure relates to a composition for a crosslinking agent for the preparation of a sensing layer or a diffusion control layer of an electrochemical biosensor comprising genipin or a derivative thereof, in which due to the properties of genipin that can be extracted and used from plants, not only it has high biocompatibility compared to conventional crosslinking agents with high toxicity, but also it can easily confirm the progress of the reaction by measuring UV or measuring the amount of amine groups present when reacting with a compound having an amine group, for example, an electron transport medium, and additionally, it has the advantage of suppressing a rapid decrease in sensor life due to high concentration of glucose while maintaining an appropriate sensitivity to glucose.

A method of measuring a quantity of a substrate contained in sample liquid is provided. This method can reduce measurement errors caused by a biosensor. The biosensor includes at least a pair of electrodes on an insulating board and is inserted into a measuring device which includes a supporting section for supporting detachably the biosensor, plural connecting terminals to be coupled to the respective electrodes, and a driving power supply which applies a voltages to the respective electrodes via the connecting terminals. One of the electrodes of the biosensor is connected to the first and second connecting terminals of the measuring device only when the biosensor is inserted into the measuring device in a given direction and has a structure such that the electrode becomes conductive between the first and second connecting terminals due to a voltage application by the driving power supply.