Abstract: A method of determining the presence or concentration of a peroxidatively active substance, such as hemoglobin, in a test sample is disclosed. The method comprises contacting the test sample with an indicator reagent composition which interacts with the peroxidatively active substance to produce a measurable or detecable color change. The indicator reagent composition comprises a redox indicator dye, a hydroperoxide, a ferric ion and a phosphorous compound having the formula ##STR1## wherein R.sub.1 or R.sub.2 are certain substituted or an unsubstituted aromatic moieties or certain polyhydric compounds, and wherein X is O, S or NH. The assay can be performed in wet phase or the composition can be incorporated into a carrier matrix. The method provides a more accurate and trustworthy assay of a test sample for a peroxidatively active substance and is especially useful in the assay of urine for occult blood.

Abstract: The present invention is a lancing device with an automatic cocking feature. The automatically cocking lancing device utilizes a firing burton loaded with a firing button spring and a drive spring connecting the firing button to a plunger. As the user presses the firing burton and compresses the firing burton spring, the user also moves the plunger until the plunger engages a latching mechanism. The latching mechanism holds the plunger in a latched position, and, as the user continues pressing the firing button, the user compresses the drive spring connected to the plunger. Before firing, the drive spring is compressed enough such that the biasing force of the drive spring is sufficient to cause the plunger to strike and drive a lancet into the user's finger. At that point, the pressing of the firing button causes the lancing device to fife. The plunger unlatches and drives the lancet into the user's finger under the biasing force of the drive spring.

Abstract: A composition, method and test device for determining the divalent cation concentration or estimating the specific gravity of a test sample are disclosed. The method utilizes a test device comprising a test pad, wherein the test pad includes a carrier matrix incorporating a reagent composition capable of interacting with divalent cations present in the test sample to produce a detectable and measurable response that correlates to the divalent cation concentration or to the specific gravity of the test sample. The reagent composition, comprising a metal-sensitive triphenylmethane dye; a buffer; an optional chelating agent; and suitable carrier, is incorporated into a carrier matrix to provide a test pad of a device useful in a divalent cation assay or a specific gravity assay of a test sample.

Abstract: The present test device provides a merocyanine protein error indicator compound. Merocyanine compounds are a new class of protein error indicators, providing an analytical tool useful in the detection of protein in a sample.

Abstract: A composition, test device and method of determining the presence or concentration of ketone bodies, and specifically D-.beta.-hydroxybutyrate, in a test sample are disclosed. The test device includes a test pad comprising a suitable carrier matrix incorporating an indicator reagent composition capable of interacting with D-.beta.-hydroxybutyrate to produce a detectable or measurable response. In addition, a new and improved indicator reagent composition, comprising a) an indicator dye that is responsive to thiols, such as a substituted isobenzothiazolone, Ellman's reagent or a derivative of Ellman's reagent: b) D-.beta.-hydroxybutyrate dehydrogenase; c) lipoamide dehydrogenase; d) D,L-lipoamide; and e) nicotinamide adenine dinucleotide, is incorporated into the carrier matrix to provide an accurate and sensitive assay of a test sample for D-.beta.-hydroxybutyrate (DHBA) in particular, and for ketone bodies in general.

Abstract: A composition, test device and method of determining the presence or concentration of proteins, such as albumin, in a liquid test sample, such as urine. The test device includes a test pad with a carrier matrix incorporating a indicator reagent composition capable of interacting with proteins to produce a detectable response. The indicator reagent composition includes an indicator dye that is capable of interacting with albumin and undergoing a detectable color transition; a buffer; a hydrophobic polymeric compound having the general structural formula: ##STR1## wherein A is ##STR2## and PO is an oxypropylene unit, EO is an oxyethylene unit, y is a number in the range of 0 to about 20, z is a number in the range of 0 to about 20, the sum y+z is a number in the range of about 2 to about 20, and R.sub.2 and R.sub.3 are selected, independently, from the group consisting of hydrogen, an alkyl group, an aralkyl group, and an aryl group;R.sub.

Abstract: A method, composition and test device for the semiquantitative determination of specific gravity of a test sample are disclosed. The method utilizes a reagent composition capable of producing a detectable and measurable response that correlates to the concentration of cations, and therefore the specific gravity, of the test sample. The reagent composition comprises: a) a polyvalent metal ion having a valence of at least two, like mercuric ion or calcium ion; b) an indicator capable of interacting with the polyvalent metal ion to provide a polyvalent metal ion-indicator complex having a first color; c) a buffer; and d) a suitable carrier. The reagent composition is used in a wet phase specific gravity assay or is incorporated into a carrier matrix, like filter paper, to provide a test pad useful in a dry phase specific gravity assay of a test sample, such as urine.

Abstract: A dual function readhead for a reflectance instrument is located in a housing for the instrument. A first light source for emitting radiation for reflectance readings and transmitting data is mounted in the readhead. In addition, a first photodetector is mounted in the readhead for detecting or receiving reflectance readings. A format or interface access port is defined in the readhead. An interface is provided that includes a second photodetector for detecting data transmitted by the first light source. A microprocessor is also provided for decoding data received by the second photodetector. A second light source may also be included with the interface for transmitting commands or data to the first photodetector. Software for controlling the operation of the first light source and the first photodetector is also provided.

Abstract: A new and improved test device and method of determining the presence or concentration of a peroxidatively active substance, such as hemoglobin, in a test sample are disclosed. The test device includes a test pad comprising a suitable carrier matrix incorporating an indicator reagent composition capable of interacting with a peroxidatively active substance to produce a detectable or measurable response. In addition, a new and improved indicator reagent composition, comprising an indicator dye, such as a redox indicator, like a benzidine indicator; a hydroperoxide; a metal ion complex; and a phosphorous compound having the general structural formula ##STR1## wherein R.sub.1 or R.sub.

Abstract: A method, composition and test device for the semiquantitative determination of specific gravity of a test sample are disclosed. The method utilizes a reagent composition capable of producing a detectable and measurable response that correlates to the concentration of cations, and therefore the specific gravity, of the test sample. The reagent composition, comprises: a) a complexing agent, like a polyelectrolyte, an ion exchange material or a chelating agent, such as a copolymer of maleic acid and methyl vinyl ether; b) a polyvalent metal ion having a valence of at least two, like ferrous ion or cobaltous ion; c) an indicator capable of interacting with the polyvalent metal ion to provide a color transition, like calmagite or gallocyanine; and d) a suitable carrier. The reagent composition is used in a wet phase specific gravity assay or is incorporated into a carrier matrix, like filter paper, to provide a test pad useful in a dry phase specific gravity assay of a test sample, such as urine.

Abstract: A test device and method of determining the presence or concentration of a predetermined ion, such as a cation of medical interest, like sodium, potassium, calcium, magnesium or lithium, in an aqueous test sample are disclosed. The test device includes a test pad comprising a hydrophilic indicator reagent composition capable of interacting with a predetermined ion, or electrolyte, to produce a detectable or measurable response. The hydrophilic indicator reagent composition consists essentially of a hydrophobic ion specific ionophore, a hydrophobic reporter substance, and a stabilizer polymer such as gelatin. The hydrophilic indicator reagent composition, either as a film or layer, or after incorporation into a suitable carrier matrix, provides a test pad of sufficient sensitivity to the predetermined ion to achieve an accurate and trustworthy electrolyte assay of an aqueous test sample, such as plasma or serum, by a dry phase test strip assay.

Abstract: Methods for blood sample preparation using reagent compositions which include a zwitterionic surfactant for sphering of cells to eliminate orientational noise. When the reagent composition including a for staining a subset of cells is reacted with an anticoagulated blood sample, and the reaction mixture is passed through the sensing region of a flow cytometer, the light scattered and absorbed by each cell is measured, the stained cells can be distinguished from the unstained cells, and when the cells are reticulocytes and mature erythrocytes, respectively, the volume and hemoglobin concentration of each reticulocyte or erythrocyte, and the hemoglobin content, mean cell volume, mean corpuscular hemoglobin concentration, and mean cell hemoglobin of the reticulocytes or erythrocytes are calculated from the measured cell-by-cell volume and hemoglobin concentration.

Abstract: The present invention provides an analytical test strip for the detection of protein in a biological sample including a novel combination of protein error indicators. The invention includes, in combination, a partially halogenated phenolsulfonephthalein protein error indicator having nitro or nitroso substituent groups in the B and/or C rings and a merocyanine protein error indicator.

Abstract: A new and improved test device and method of determining the presence or concentration of a predetermined analyte, such as glucose, cholesterol or occult blood, in a test sample are disclosed. The test device includes a test pad comprising a suitable carrier matrix incorporating an indicator reagent composition capable of interacting with the predetermined analyte to produce a detectable or measurable response.

Abstract: The present invention provides a merocyanine protein error indicator compound. Merocyanine compounds are a new class of protein error indicators, providing an analytical tool useful in the detection of protein in a sample.

Abstract: A method of manufacturing a test device for determining the presence and concentration of proteins, such as albumin or Bence Jones proteins, in a test sample. The test device includes a carrier matrix incorporating a reactant system capable of interacting with proteins to produce a visually or instrumentally detectable and/or measurable response. The carrier matrix of the device can include commonly used bibulous matrices, such as filter paper, or a nonbibulous protein-permeable strip, membrane or layer of a polymerized urethane-containing composition. In addition, a reactant system, including a dual indicator reagent system, such as bromophenol blue, methyl orange and, if necessary, a suitable buffer, is incorporated into the carrier matrix to provide improved color resolution and increased sensitivity to proteins, thereby affording a more accurate and trustworthy protein assay of test samples, such as urine.

Abstract: The present invention is directed to the use of polymer blend films consisting of polycarbonate and polyalkylene terephthalate supports for diagnostic test strips.

Abstract: A position sensing and motion verification assembly for a motor-driven mechanism includes a base member on which a sensor pattern is fabricated. The sensor pattern includes a predetermined orientation of tabs and notches of varying widths. A home position is defined in the sensor pattern and the polarity of the pattern is inverted on opposite sides of the home position. A single sensor such as an optical interrupter is mounted in the assembly in a position relative to the sensor pattern to sense the tabs and notches.

Abstract: Test compositions, indicators, and test device are provided which are capable of generating different hues at different analyte concentrations. The compositions are capable of generating a yellow hue in situ. Visual tests for clinically important analytes, such as glucose, are determined by use of two independent catalytic systems which are reactive with reduced nicotinamide adenin dinucleotide to produce a range of hues; the particular hue produced depending on the concentration of the analyte. The invention provides a test device for the determination of analyte, e.g. glucose, in body fluid which exhibits a RAINBOW of hues, the particular final hue produced depending on the analyte concentration.