Abstract: A preservative mixture in particular for preserving diagnostic test liquids, contains the sodium salt of mercaptopyridine-N-oxide together with a further preserving substance. A diagnostic test kit according to the invention contains mercaptopyridine-N-oxide sodium salt, a compound from the isothiazolone group and in particular 2-alkyl-3-(2H)isothiazolone hydrochloride with 1 to 8 C atoms in the 2-alkyl group or a preservative mixture according to the invention as the preservative for one or several test liquids of the test kit.

Abstract: A method and apparatus for the controlled instrumentation processing of cells and other particles with a filter device measures a parameter of the flow through the filter device of a fluid carrying the particles. A measure of the change of fluid flow through the filter device yields desired information for quantizing the particles and for quantizing the obstruction of the filter device by the particles. The method and apparatus typically operate automatically. Cytological test methods and instruments can employ the invention to quantize and to collect cells.

Abstract: Systems and methods for inducing and detecting sample analyte(s) identifying fluorescence are disclosed. In particular, a system which includes at least two fiber optic means, within a "throw-away" modular component system component with at least four ports, in which sample analyte fluorescence is caused to occur, by the application of energy to sample analyte(s), is disclosed. The present invention system provides that sample analyte(s) fluorescence inducing energy be entered via an optic fiber means and that produced fluorescence be provided to a detector system via a second optic fiber means. A preferred source of sample analyte(s) fluorescence inducing energy includes lasers, and a preferred method by which to provide sample analyte(s) to the present invention system involves electrophoresis.

Abstract: The present invention provides a microfabricated sensor and a method capable of rapid simultaneous measurement of multiple analytes in a fluid sample. The sensor is inexpensive, disposable and portable, and requires only microliters of sample, a particular advantage with precious fluids such as blood. The sensor utilizes diffusion between layered laminar streams rather than side by side streams. This allows multiple side by side channels for simultaneous detection of multiple analytes. In the sensor, a sample stream and a carrier stream flow in layers, one on top of the other, and one or more reagents are introduced to the bottom of the carrier stream through either a fluid or a solid reagent inlet. The reagent contains reagent particles which, in the presence of the analyte, have a detectable change in a property. The analyte diffuses into the carrier stream where it interacts with reagent particles and is detected by optical, electrochemical or other devices.

Abstract: When adsorbed gas is analyzed after metal, ceramics or metallic salt has been left in an environmental atmosphere for a predetermined period of time, an average concentration of specific gas over a long period of time can be accurately measured with an inexpensive small apparatus. Especially, porous metal or ceramics (transition metal oxide) are excellent in selective adsorption properties for NO.sub.x, porous ceramics (rare earth element oxide) are excellent in selective adsorption properties for CO.sub.2, and a specific chloride such as copper chloride and silver chloride is excellent in selective adsorption properties for SO.sub.2. A test kit accommodating such test pieces in a case, a protective case for the test kit to put the test kit into practical use, an umbrella and a forced air blowing unit are also disclosed.

Abstract: To determine the total organic carbon content of a flowing liquid in a continuous process, water and oxidizing agents enter lower ports in a continuous column and flow upwardly along a helical path with air gaps as they are mixed. The helical reaction path is formed by a helical glass cylinder between an ultraviolet lamp and outer wall of a continuous glass tube to cause rapid motion of the liquid. An ultraviolet lamp extends downwardly through the center of the column so that the outer confining surface of the helical path is the outer surface of the ultraviolet lamp, causing the liquid to move rapidly in intimate contact with the ultraviolet lamp to receive intense radiation. An air gap permits escape of air and reduces bubble size to reduce plug flow.

Abstract: The present invention relates to the direct quantitative determination of cholesterol and involves the formation of a spectrophotometrically active product of cholesterol obtained by contacting cholesterol with an acyl compound and a perchlorate effective to form the spectrophotometrically active product.

Abstract: When adsorbed gas is analyzed after metal, ceramics or metallic salt has been left in an environmental atmosphere for a predetermined period of time, an average concentration of specific gas over a long period of time can be accurately measured with an inexpensive small apparatus. Especially, porous metal or ceramics (transition metal oxide) are excellent in selective adsorption properties for NO.sub.x, porous ceramics (rare earth element oxide) are excellent in selective adsorption properties for CO.sub.2, and a specific chloride such as copper chloride and silver chloride is excellent in selective adsorption properties for SO.sub.2. A test kit accommodating such test pieces in a case, a protective case for the test kit to put the test kit into practical use, an umbrella and a forced air blowing unit are also disclosed.

Abstract: We have fabricated miniature planar IR waveguides of thickness 30-50 .mu.m, consisting of 12-mm long, 2-mm wide strips of Ge supported on ZnS substrates. Evidence for efficient propagation of broadband IR light through these waveguides is provided by the presence of characteristic high and low frequency optical cut-offs of Ge; by the observation of an oscillatory interference pattern in the transmittance spectrum, which exhibits a dependence on waveguide thickness and propagation angle closely matching waveguide theory; and by the detection of strong evanescent-wave absorption from small (2 mm.sup.2) droplets of liquid, e.g. water, on the waveguide surface. As also predicted by theory, the surface sensitivity (detected light absorbance per unit area of sample-waveguide contact) was shown to increase as a function of incidence or bevel angle.

Abstract: Reference controls comprised of aldehyde-fixed white blood cells stabilized red blood cells and simulated blood platelets exhibiting a white blood cell histogram profile that is substantially that of whole blood are obtained by the addition of a lipoprotein to the control and an antioxidant to inhibit lysis of stabilized red blood cells by said lipoprotein.

Abstract: An improved method of detecting latent bloodstains using a thickened solution of fluorescin which is applied to a surface, activated by application of hydrogen peroxide and visualized as fluorescein under ultraviolet (UV) light is disclosed.

Abstract: A method and a device for optically ascertaining the mutual binding of a first and a second reactant are described. Use is made of the fact that a dipolar layer (7) having a non-linear optical behavior is formed upon a reaction between the two reactants. The formation of such a layer is ascertained by illuminating the substance with radiation (8) having one or two frequencies, and by detecting whether radiation (10) from the substance contains a component at a frequency which is twice the frequency, or a mixed term of the frequency of the radiation incident on the substance.

Abstract: Systems and methods treat biological fluids carrying contaminants by photoactivating materials mixed with the fluids. The systems and methods quantify the photoreactions that occur in a manner that permits correlation with clinical results.

Abstract: Oxygen sensor for measuring resistance as a function of oxygen partial pressure, made of alkaline-earth-doped perovskitic lanthanum ferrites with the general formulaLa.sub.1-x Me.sub.x FeO.sub.3-.delta.where Me is one of alkaline earth metals, Mg, Ca, Sr, and Ba, x is a degree of doping of the lanthanum ferrites. The oxygen sensor oxygen deficit of anion is 6=0 to 0.25, and the degree of doping of the lanthanum ferrites is x=0.1 to 0.3 and is selected to provide a temperature independent resistance property to the oxygen sensor in a lean range.

Abstract: A channel-cell system is provided for detecting the presence and/or measuring the presence of analyte particles in a sample stream comprising: a) a laminar flow channel; b) two inlets in fluid connection with the laminar flow channel for respectively conducting into the laminar flow channel (1) an indicator stream which may comprise an indicator substance which indicates the presence of the analyte particles by a detectable change in property when contacted with the analyte particles, and (2) the sample stream; c) wherein the laminar flow channel has a depth sufficiently small to allow laminar flow of the streams and a length sufficient to allow particles of the analyte to diffuse into the indicator stream to the substantial exclusion of the larger particles in the sample stream to form a detection area; and d) an outlet for conducting the streams out of the laminar flow channel to form a single mixed stream.

Abstract: A method for determining total chlorine amount present in a sample by mixing the sample with a benzidine indicator solution comprising a benzidine compound capable of forming a dye by a reaction with a chlorine, wherein the hue of the formed dye changes depending upon the mole ratio of the chlorine to benzidine compound and determining the total chlorine amount from the hue. A kit for practicing the method incudes the indicator and a color scale for the hues of the dye.

Abstract: A carbon monoxide sensing system is provided including a garage having an automatic door adapted to open only upon the receipt of an activation signal. Further provided is a carbon monoxide sensor positioned within the garage and connected to the automatic door for transmitting the activation signal upon the detection of an amount of carbon monoxide which exceeds a predetermined amount. A light beam detector is adapted to generate the activation signal only upon the detection of vehicle within the garage. Also included is a control mechanism connected between the carbon monoxide sensor, light detection and the door opener for allowing the transmission of the activation signal to the door opener only upon the receipt of the activation signal from the light beam detector.

Abstract: A method using concentrated aqueous solutions of sodium cobaltinitrite and a rhodamine dye is described which can be used to identify concrete that contains gels formed by the alkali-silica reaction (ASR), and to identify degraded concrete which results in a porous or semi-permeable paste due to carbonation or leaching. These solutions present little health or environmental risk, are readily applied, and rapidly discriminate between two chemically distinct gels; K-rich, Na--K--Ca--Si gels are identified by yellow staining, and alkali-poor, Ca--Si gels are identified by pink staining.

Abstract: The present invention is a collection container assembly comprising a container having a microporous partition so as to reduce the internal volume of the container wherein the external dimensions of the container are substantially the same as a standard-sized blood collection tube but with a reduced internal volume.

Abstract: A colorimetric method is provided for determining the presence or absence of a corrosion-inhibitory level of carboxylate anion in used aqueous engine coolant.