Abstract: Determination of an analyte with increased accuracy is achieved by electrochemically determining an initial analyte concentration, performing a plurality of amperometric/potentiometric switching cycles, observing a characteristic of the signal during each of the plurality of switching cycles, determining an averaged value for the characteristic of the signal, and correcting the initial measurement value to arrive at a final measurement value of analyte concentration or rejecting the initial measurement value depending on the averaged value of the characteristic of the signal. The characteristic of the signal that is observed is not per se indicative of the amount of analyte present in a sample. Rather, it is a characteristic of the signal that reflects the quality of the electrodes, the extent of fill of the electrochemical cell or characteristics of the sample other than analyte concentration such as oxygen levels or hematocrit.

Abstract: A filling apparatus for filling a microplate. The microplate can comprise a plurality of wells each sized to receive an assay. A substrate can comprise a first surface and an opposing second surface, a first assay input port for receiving the assay disposed on the first surface, a plurality of staging capillaries extending through the substrate, and a first plurality of microfluidic channels fluidly coupling the first assay input port with at least one of the plurality of staging capillaries. Each of the plurality of staging capillaries can comprise an inlet and an outlet and be sized to receive the assay.

Abstract: A method is provided for determining analyte concentrations, for example glucose concentrations, that utilizes a dynamic determination of the appropriate time for making a glucose measurement, for example when a current versus time curve substantially conforms to a Cottrell decay, or when the current is established in a plateau region. Dynamic determination of the time to take the measurement allows each strip to operate in the shortest appropriate time frame, thereby avoiding using an average measurement time that may be longer than necessary for some strips and too short for others.

Abstract: A test strip and analytical apparatus have pin connections permitting the definition of geographic regions or of particular customers. A test strip made for use in a particular region or for a particular customer will have pin connections matching features of the apparatus made for use in that region or by that customer. Insertion of the strip into the apparatus does not merely turn on the apparatus, but provides the regional or customer coding. Analog switches within the apparatus allow coding of a larger number of distinct regions or customers than would otherwise be possible, all without degrading the quality of the measurements made of the fluid being tested. Conductive paths in the strips permit testing the strips during manufacture so as to detect quality lapses regarding the printing or deposition of the paths.

Abstract: A method of using a standard to correct for variability in sample handling, can comprise (a) adding a template of known concentration to an assay comprising a sample; (b) preamplifying the assay; (c) amplifying the assay; (d) collecting data during the amplifying; and (e) correcting the data using a comparison of data collected from the template to data collected from the sample.

Abstract: A filling apparatus for filling a microplate. The microplate can comprise a plurality of wells each sized to receive an assay. A substrate can comprise a first surface and an opposing second surface, a first assay input port for receiving the assay disposed on the first surface, a plurality of staging capillaries extending through the substrate, and a first plurality of microfluidic channels fluidly coupling the first assay input port with at least one of the plurality of staging capillaries. Each of the plurality of staging capillaries can comprise an inlet and an outlet and be sized to receive the assay.

Abstract: In a high-density sequence detection system, an apparatus for transporting a microplate. A control system provides a thermocycler control signal to regulate a desired thermal output of a thermocycler block. A frame has a first side, a second side, and an opening that extends through the first side and the second side. A window is positioned in the opening and a circumferential seal is positioned around a periphery of the opening at the second side. The seal has a peripheral lip that seals against the microplate. A clamp is adapted to engage and displace the frame from an unclamped position to a clamped position, wherein in the unclamped position, the microplate is displaced away from the thermocycler block and in the clamped position, the clamp urges the microplate against the thermocycler block. In some embodiments the peripheral lip is positioned radially inward of the periphery of the opening.

Abstract: A method is provided for determining analyte concentrations, for example glucose concentrations, that utilizes a dynamic determination of the appropriate time for making a glucose measurement, for example when a current versus time curve substantially conforms to a Cottrell decay, or when the current is established in a plateau region. Dynamic determination of the time to take the measurement allows each strip to operate in the shortest appropriate time frame, thereby avoiding using an average measurement time that may be longer than necessary for some strips and too short for others.

Abstract: Methods for normalizing output from an instrument employing a reference standard or non-fluorescing substance disposed within at least one of a plurality of reaction chambers. The method comprises collecting and analyzing a signal associated with the reference standard or non-fluorescing substance to determine a normalizing bias. The normalizing bias is then applied to the data signal collected from a remainder of the plurality of reaction chambers.

Abstract: A sealing cover roll for use in sealing a microplate comprising an elongated carrier liner having a first surface and a second surface. A plurality of sealing covers are releasably carried on the first surface of the elongated carrier liner. Each of the plurality of sealing covers comprises a base stock and an adhesive. The adhesive is operable to retain the base stock to the elongated carrier liner and permit release of the base stock and the adhesive from the elongated carrier liner. A roll core supports a rolled configuration of the elongated carrier liner such that the first surface of the elongated carrier liner faces toward the roll core when rolled.

Abstract: A filling apparatus for filling a microplate. The microplate having a plurality of wells each sized to receive an assay. The filling apparatus can comprise an assay input layer having a first surface and an opposing second surface. The assay input layer can comprise an assay input port extending from the first surface to the second surface and at least one pressure nodule extending from the second surface. An output layer can comprise a plurality of staging capillaries each having an inlet and an outlet. A intermediate layer can be disposed between the assay input layer and the output layer. The intermediate layer can be flexible and comprise a plurality of microfluidic channels and a flow aperture being in fluid communication with the assay input port and the plurality of microfluidic channels.

Abstract: A method for simultaneously determining a genetic expression profile for an individual member of a species relative to an entire standard genome for the species. The method can comprise distributing a liquid sample into an array of reaction chambers of a substrate. The array can comprise a primer set and a probe for each polynucleotide target along the entire standard genome. The liquid sample can comprise substantially all genetic material of the member. Each of the reaction chambers can comprise the primer set and the probe for at least one of the polynucleotide targets and a polymerase. The method can further comprise amplifying the liquid sample in the array, detecting a signal emitted by at least one of the probes, and identifying the genetic expression profile in response to the signal.

Abstract: The presence of a select analyte in the sample is evaluated in an an electrochemical system using a conduction cell-type apparatus. A potential or current is generated between the two electrodes of the cell sufficient to bring about oxidation or reduction of the analyte or of a mediator in an analyte-detection redox system, thereby forming a chemical potential gradient of the analyte or mediator between the two electrodes After the gradient is established, the applied potential or current is discontinued and an analyte-independent signal is obtained from the relaxation of the chemical potential gradient. The analyte-independent signal is used to correct the analyte-dependent signal obtained during application of the potential or current.

Abstract: Partial fill of an electrochemical test strip is determined by making a DC determination of double layer capacitance from charging or discharging charge on a test strip containing sample, for example a blood sample to be tested for glucose. The measured double layer capacitance is compared to a reference value. The double layer capacitance may be determined as an integral or differential capacitance. Double layer capacitance may also be used for quality control to monitor the quality of electrode formation, particularly in strips using screen printed electrodes.

Abstract: A substantially planar electrochemical test strip for determination of the presence and/or quantity of an analyte in a sample is provided that has a first electrode, a first connector including two contact pads, and a first conductive lead extending between the first electrode and the first connector to establish a path for conduction of an electrical signal between the first electrode and the first connector; a second electrode, a second connector including one or more contact pads, and a second conductive lead extending between the second electrode and the second connector to establish a path for conduction of an electrical signal between the second electrode and the second connector, and a sample chamber for receiving a sample. The first and second electrode are disposed to contact a sample within the sample chamber such that an electrochemical signal is generated. The contact pad or pads of the second connector are between the contact pads of the first connector when viewed in the plane of the test strip.

Abstract: Measurement of the series resistance of a working and counter electrode pair in an electrochemical test strip provide error detection for multiple variations in the quality of the test strip, as well as the operation of strip in the test meter. In particular, a single measurement of series resistance can be used to detect and generate an error message when an incorrect reading is likely to result due to (1) damaged electrode tracks, (2) fouled electrode surfaces, (3) dirty strip contacts, or (4) short circuit between the electrodes.

Abstract: An assay card and devices and methods for isolating chambers on the assay card are described. The assay card comprises a substrate formed of one or more materials, e.g., plastic, having a softening temperature, the substrate defining channels communicating with respective reaction chambers. The assay card may be heated in a region of the channels to at least the softening temperature. The softened plastic may be deformed, e.g., with a tool which may or may not also provide the heat for softening the substrate. In this manner, the plastic of the substrate may be caused to at least partially obstruct the channels, thereby isolating the reaction chambers. The invention also relates to a method of manufacturing a tool device that includes pins for heating and deforming an assay card.

Abstract: The presence of a select analyte in the sample is evaluated in an an electrochemical system using a conduction cell-type apparatus. A potential or current is generated between the two electrodes of the cell sufficient to bring about oxidation or reduction of the analyte or of a mediator in an analyte-detection redox system, thereby forming a chemical potential gradient of the analyte or mediator between the two electrodes After the gradient is established, the applied potential or current is discontinued and an analyte-independent signal is obtained from the relaxation of the chemical potential gradient. The analyte-independent signal is used to correct the analyte-dependent signal obtained during application of the potential or current.

Abstract: A method and apparatus for electrochemical detection of analyte in a sample makes use of a binding interaction and relies on the discovery that asymmetric distribution of a redox enzyme between two electrodes that occurs when a redox enzyme-containing reagent is immobilized at the surface of one electrode can be detected as a chemical potential gradient arising from an asymmetry, in the distribution of oxidized or reduced redox substrate. This chemical potential gradient can be detected potentiometrically by observing the potential difference between the electrodes in an open circuit, or amperometrically by observing the current flow between the electrodes when the circuit is closed. In both cases, the observation of asymmetry can be done without the application of an external potential or current to the electrodes.

Abstract: An electrochemical test strip is formed from a first insulating substrate layer, a second substrate layer, and an intervening insulating spacer layer. An opening in the insulating spacer layer defines a test cell which is in contact with the inner surface of the first substrate on one side and the inner surface of the second substrate on the other side. The size of the test cell is determined by the area of substrate exposed and the thickness of the spacer layer. Working and counter electrodes appropriate for the analyte to be detected are disposed on the first insulating substrate in a location within the test cell. The working and counter electrodes are associated with conductive leads that allow The second substrate is conductive at least in a region facing the working and counter electrodes. No functional connection of this conductive surface of the second substrate to the meter is required.