Abstract: Disclosed is a method for determining the concentration of an analyte in a liquid test sample. The method involves the use of colloidal sized metal particles, which exhibit a spectral response in the agglomerated state which is detectably different than in their unagglomerated state, which bear specific binding partners for the analyte in question on their surface. The specific binding partner treated colloidal particles are combined in a buffered, aqueous medium with a destabilizer material capable of destabilizing the specific binding partner-colloidal particle conjugates thereby permitting the particles to agglomerate. Also included in the liquid medium is a polymer bearing multiple analyte or analyte analog molecules along its surface which serves to protect the specific binding partner coated metal particles from dissociation by the destabilizing agent.

Abstract: A sensor dispensing instrument is adapted to receive a generally circular sensor pack containing a plurality of blood glucose sensors. Each of the sensors are disposed in sensor cavities, each of which is in fluid communication with a corresponding desiccant cavity and has a support wall that assists in directing the sensor as its being ejected from the cavity. The sensor pack is loaded on an indexing disk in the instrument such that when a slide actuator on the instrument is moved toward a testing position, a feed mechanism engaged by the slide actuator moves a knife blade thereon toward one of the sensor cavities. The knife blade pierces a portion of a foil covering the sensor cavity and engages the sensor disposed in the cavity to thereby eject the sensor from the sensor cavity.

Abstract: Disclosed is a method for the determination of creatinine in urine which involves contacting a urine test sample with a reagent system containing Cu.sup.+2, a hydroperoxide and an oxidizible dye which provides a detectable response when oxidized in the presence of a pseudoperoxide. The reagent system also includes a buffer to maintain the urine's pH within the range of 6.6 to 8.0 and a chelating agent for the cupric ions to prevent oxidation of the dye in the absence of creatinine.

Abstract: The present invention relates to a control solution for and a method of testing the performance of an electrochemical sensing device for determining the concentration of an analyte in a blood sample. The device contains a sensing means having a working electrode on which is deposited an enzyme capable of reacting with the analyte to provide electrons and a mediator to shuttle the electrons to the surface of the working electrode. The control solution is formulated so that the device will recognize the control solution as being something other than blood and automatically exclude the results obtained with the control solution from its memory unit.

Abstract: Disclosed is a method for the chemical synthesis of deoxypyridinoline (DPD). The synthesis involves the preparation of a protected 3-hydroxypyridinium starting with a N.alpha.-protected lysine and a 5,6-epoxy-2-N-protected-O-protected-(2S)-2-aminohexanoate with subsequent deprotection to provide the desired DPD.

Abstract: Disclosed is an improvement in the method of determining protein in an aqueous fluid such as urine by contacting the fluid with a reagent system of a buffer and a protein error indicator. The improvement involves carrying out the determination in the presence of a glass/cellulose combination.

Abstract: Disclosed are novel folic acid-alkaline phosphatase conjugates useful in a competitive immunoassay for folic acid in a biological fluid such as serum. A preferred conjugate involves a folate hapten bound to (N-Succinimidyl?4-iodoacetyl!aminobenzoate) through a 1,12-diamino-4,9-dioxadodecanyl spacer arm.

Abstract: A method and apparatus are provided for marking predetermined events with a biosensor. The biosensor includes a sensor for receiving a user sample to be measured and a processor for performing a predefined test sequence for measuring a predefined parameter value. A memory is coupled to said processor for storing predefined parameter data values. A marker member is manually coupled by the user to the processor for selectively marking one of a plurality of predetermined events with a stored predefined parameter data value.

Abstract: Disclosed is a dry reagent system involving an absorbent carrier incorporated with a dye precursor which undergoes a detectable response in the presence of creatinine under strongly basic conditions and which also contains a moderating agent for the strong base which is a polyglycol or a polymerized quaternary ammonium salt.

Abstract: A sensor for use in a sensor dispensing instrument so that fluids can be tested when the sensor is ejected from within a sensor cavity of a sensor pack sealed by a foil. The sensor has a generally flat, rectangular shape, is formed by a base and a lid, and has perpendicularly extending longitudinal and transverse axes. A notch in a rear end of the sensor is engaged by a knife blade within the sensor dispensing instrument as the sensor is being ejected through the foil. A front testing edge of the lid overhangs a front testing edge of the base of the sensor. One side edge of the sensor adjacent the front edges of the base and lid is beveled at about a 25.degree. angle. The front base edge extends from the beveled side portion across the entire remaining width of the sensor at an angle of approximately 10.degree. with respect to the transverse axis. A portion of the front lid edge extends from the beveled side portion across a significant portion of the width of the sensor at an angle of about 15.degree.

Abstract: Apparatus and method are provided for determining the concentration of an analyte in a fluid test sample by applying the fluid test sample to the surface of a working electrode which is electrochemically connected to a reference electrode which surface bears a composition comprising an enzyme specific for the analyte. A mediator is reduced in response to a reaction between the analyte and the enzyme. An oxidizing potential is applied between the electrodes to return at least a portion of the mediator back to its oxidized form before determining the concentration of the analyte to thereby increase the accuracy of the analyte determination. Following this initially applied potential, the circuit is switched to an open circuit or to a potential that substantially reduces the current to minimize the rate of electrochemical potential at the working electrode. A second potential is applied between the electrodes and the current generated in the fluid test sample is measured to determine analyte concentration.

Abstract: A sensor dispensing instrument (20) includes a sensor magazine (26) that contains a plurality of blood glucose sensors (38) disposed in sensor slots (30A-J). Each of the sensor slots (30A-J) is in fluid communication with a desiccant cavity (50A-J) in which desiccant material is disposed. The front and rear walls (34, 32) of the sensor magazine (26) are sealed with burst foils (40, 42) so as to seal the sensor slots (30A-J) and the desiccant cavities (36A-J). The sensor instrument (20) has an outer housing (22) with a laterally extending magazine opening (24) adapted to receive the sensor magazine (26). A pivot rod (28) is moved through the magazine (26) and is locked into an operating position. The magazine (26) is rotated on the pivot rod (28) until a detent arm (48) on the instrument housing (22) engages a detent groove (50A-J) on the magazine (26) to position the magazine (26) in a sensor feeding position.

Abstract: Disclosed are a method and device for the determination of specific gravity in aqueous systems, particularly urine. The invention improves upon the known systems for detecting specific gravity by the use of a polyelectrolyte polymer and pH indicator by the addition of a crown ether ionophore which enhances the ability of the reagent system to indicate the fluid's specific gravity.

Abstract: A sensor dispensing instrument is adapted to receive a generally circular sensor pack containing a plurality of blood glucose sensors. Each of the sensors are disposed in sensor cavities, each of which is in fluid communication with a corresponding desiccant cavity and has a support wall that assists in directing the sensor as its being ejected from the cavity. The sensor pack is loaded on an indexing disk in the instrument such that when a slide actuator on the instrument is moved toward a testing position, a feed mechanism engaged by the slide actuator moves a knife blade thereon toward one of the sensor cavities. The knife blade pierces a portion of a foil covering the sensor cavity and engages the sensor disposed in the cavity to thereby eject the sensor from the sensor cavity.

Abstract: The present invention involves a method for the preparation of substituted 3-(phenylimino)-3 H-phenothiazines or phenoxazines which method involves reacting phenothiazine or phenoxazine with an aromatic amine in the presence of periodic acid as coupling agent.

Abstract: Apparatus and method are provided for determining the concentration of an analyte in a fluid test sample by applying the fluid test sample to the surface of a working electrode which is electrochemically connected to a reference electrode which surface bears a composition comprising an enzyme specific for the analyte. A mediator is reduced in response to a reaction between the analyte and the enzyme. An oxidizing potential is applied between the electrodes to return at least a portion of the mediator back to its oxidized form before determining the concentration of the analyte to thereby increase the accuracy of the analyte determination. Following this initially applied potential, the circuit is switched to an open circuit or to a potential that substantially reduces the current to minimize the rate of electrochemical potential at the working electrode. A second potential is applied between the electrodes and the current generated in the fluid test sample is measured to determine analyte concentration.

Abstract: Disclosed is an improvement to the method for the detection of creatinine in which creatinine, in aqueous solution, is contacted with a dry reagent system of an indicator for creatinine. The assay is carried out at a pH above about 11.5 which is maintained by an alkaline material. The improvement involves packaging the reagent system with a material capable of absorbing CO.sub.2 and at least some ambient water vapor. This inhibits the formation of carbonic acid thereby reducing the neutralization of the alkaline reagent system during storage to increase the shelf life and decrease the variability of the system.

Abstract: Disclosed is an test for the detection of protein in urine by the use of a reagent system containing a buffer and a protein error indicator. The method involves the use of tartaric acid as cation sensing buffer in combination with a non-cation sensing buffer as the buffer system in order to reduce the incidence of false positive results while using less total buffering material.

Abstract: A sensor dispensing instrument is adapted to receive a generally circular sensor pack containing a plurality of blood glucose sensors. Each of the sensors are disposed in sensor cavities, each of which is in fluid communication with a corresponding desiccant cavity and has a support wall that assists in directing the sensor as its being ejected from the cavity. The sensor pack is loaded on an indexing disk in the instrument such that when a slide actuator on the instrument is moved toward a testing position, a feed mechanism engaged by the slide actuator moves a knife blade thereon toward one of the sensor cavities. The knife blade pierces a portion of a foil covering the sensor cavity and engages the sensor disposed in the cavity to thereby eject the sensor from the sensor cavity.

Abstract: A method for determining the concentration of analyte in a test fluid by immunochromatography techniques which involves quantitatively determining the signals from captured analyte/labeled binding partner complex by an instrument, e.g. reflectance spectrometer. In a preferred embodiment, a reflectance reading is determined for the captured complex and uncomplexed labeled binding partner which is captured in a separate zone of the immunochromatographic strip and the ratio of these reflectances is used to provide additional quantitation to the assay method.