Abstract: A composite ion selective electrode comprising a calcium ion selective electrode member and a hydrogen ion selective electrode member which is characterized in that a calcium ion selective membrane of the calcium ion selective electrode member has a thickness of 5 to 30 &mgr;m, and the hydrogen ion selective membrane of the hydrogen ion selective electrode member contains tri-n-dodecyl-amine and trisethylhexyl trimellitate. Each of the calcium ion selective electrode member and the hydrogen ion selective electrode member can be employed singly.

Abstract: Whether or not there remains a frameless chemical analysis film in a cartridge in which a plurality of the frameless chemical analysis films are stacked is judged by a film presence detector disposed in a second position different from a position where a film takeout mechanism takes out the frameless chemical analysis films from the cartridge so that the film presence detector does not interfere with the film takeout mechanism.

Abstract: An improved homogeneous enzyme immunoassay process for quantitatively analyzing an antigen by determining the change in the enzymatic activity caused by a reaction between the antigen and an enzyme-labeled antibody. The antigen is reacted with an enzyme-labeled antibody, followed by the reaction with a second antibody capable of recognizing and binding to a different epitope and then with a third antibody capable of recognizing and binding to the second antibody. The enzymatic activity of the labeling enzyme is determined by a water-insoluble substrate. Using the water-insoluble substrate, steric hindrance is enhanced. A highly-sensitive analysis can be carried out by a simple operation even when the antigen has a molecular weight falling within an intermediate range, for example, a range of M.W. 10,000 to 70,000.

Abstract: The blood filter cartridge of the invention can be used as a sample cup of an analyzer without sucking bubbles, which comprises a blood filtering material, a holder containing the blood filtering material and having a blood inlet and a filtrate outlet, and a filtrate receiver for receiving filtrate discharged from the filtrate outlet, the filtrate receiver has an upper end having a difference in height or structure for returning the filtrate from the upper end of the filtrate receiver to the filtrate outlet.

Abstract: A reactive solid carrier favorably employable for manufacturing DNA chip is composed of a solid carrier and a plurality of vinylsulfonyl groups or their reactive precursors each of which is fixed onto a surface of the solid carrier by covalent bonding via a linking group, and a method for producing a DNA chip is performed by bringing the reactive solid carrier into contact with nucleotide derivatives or their analogues having a reactive group which is reactive with the vinylsulfonyl group or reactive precursor fixed to the solid carrier.

Abstract: The invention provides a blood filter cartridge which is made so that the filtrate discharged from the filtrate outlet is not drawn back to the inside of the filtering chamber. The blood filter cartridge includes a blood filtering material, a holder containing the blood filtering material and having a blood inlet and a filtrate outlet, and a filtrate receiver which receives the filtrate discharged from the filtrate outlet. The blood filter catridge is provided with a means for preventing the filtrate in the filtrate receiver from returning to inside of the holder upon finishing filtration. Such means include the following: removing opposite faces around the filtrate outlet, making length of lower end of the filtrate outlet 0.8 mm or more, smoothing surface around the filtrate outlet, and forming surface around the filtrate outlet by a material having a small surface energy.

Abstract: A dry analytical substantially flat film chip for use as an analytical element composed of a support, at least one reagent layer and a spreading layer laminated in this order. The chip is suitable for use as is as an analytical element for liquid samples. The chip further has means for restraining a liquid sample applied to its surface from spreading beyond a predetermined area of the surface. The restraining means may be a fused nonporous area of the spreading layer or may be a portion or area of the spreading layer which has been clogged with a hydrophobic or lipophilic material to render it nonporous. The inventive film chip, in addition, provides means for preventing fraying of the edges of the porous spreading layer as well as the prevention of the generation of fiber dust during cutting of the chip.

Abstract: A chemical analysis film chip is prepared by integrally laminating a reagent layer and a spreading layer on a support sheet in this order, or by integrally laminating a water absorbing layer having a hydrophilic polymer as a major component and a porous outermost layer containing therein a reagent on a support sheet in this order, or by superposing a porous layer containing therein a reagent on a support sheet.

Abstract: A spotting tip includes a tip body which is fitted on the end of a nozzle for sucking liquid contained in a container and inserted into the liquid in the container through a mouth of the container, and a lid member which is brought into contact with the mouth of the container and closes the space between the tip and the edge of the mouth when the tip is inserted into the container to a predetermined depth. At least one fine communicating passage is formed in at least one of the lid member and the tip body to communicate the inside and outside spaces of the container on opposite sides of the lid member.

Abstract: The concentration of an analyte in a sample liquid is determined on the basis of the optical density of a chemical analysis element spotted with the sample liquid according to a standard curve representing the relation between the concentration and the optical density of the analysis element which is obtained when the concentration is measured using an analysis element of a first lot. A plurality of first standard liquids containing the analyte in known levels are spotted onto analysis elements of a second lot, the concentrations of the analyte in the first standard liquids are determined according to the standard curve and a first calibration curve for correcting the concentrations of the analyte is prepared.

Abstract: When spotting a sample liquid onto a plurality of frameless chemical analysis films, a predetermined amount of the sample liquid is sucked into a spotting tip, the lower end of the spotting tip is brought into contact with the surface of each chemical analysis film and the pressure in the spotting tip is increased to discharge the sample liquid therein onto the surface of the chemical analysis film while lifting the spotting tip away from the surface of the film.

Abstract: A dry chemical analysis film deposited with a sample liquid is inserted into an incubator to be incubated at a predetermined temperature, a coloring reaction of the chemical analysis film is measured after the incubation and then the chemical analysis film is discharged from the incubator. A plurality of chemical analysis films are subjected to these steps one by one after the preceding chemical analysis film is discharged from the incubator.

Abstract: When determining an activity of particular predetermined ions in a sample liquid by use of a device for measuring ionic activity including a pair of ion-selective electrodes which are selectively responsive to particular predetermined ions, a pair of spotting holes through which a sample liquid and a reference liquid are respectively supplied to the ion-selective electrodes and a porous bridge which communicates the spotting holes with each other so as to permit the sample liquid and the reference liquid spotted to the spotting holes to electrically contact with each other, for instance, the sample liquid is first spotted to one of the spotting holes of the device for measuring ionic activity with a first spotting tool, and at least one of the first spotting tool and the device for measuring ionic activity is thereafter moved to remove the first spotting tool away from the device for measuring ionic activity.

Abstract: In a method for mixing a small amount of a liquid sample with a second liquid, the liquid sample is first fed into a mixing vessel. Thereafter, the second liquid is discharged from an orifice of a second liquid pipette tip into the vessel, and the liquid sample and the second liquid are thereby stirred with each other. The small amount of the liquid sample is thus efficiently stirred by the second liquid and is thereby uniformly mixed with the second liquid. Also, the liquid sample and the second liquid are mixed with each other in an accurate mixing ratio.

Abstract: A cartridge for storing a plurality of stacked chips having an exit for taking out the end dry analytical film chip one by one which are pushed toward the exit, and a flexible engager for inhibiting the discharge of the end chip. The exit and the engager are provided at an end portion of a side wall of the casing, the opening being provided at an end of the casing, and the flexible engager has a strength capable of releasing the end chip from the conveyor but is also capable of holding the second end, wherein the exit and the engager are provided at an end portion of a side wall of the casing, the opening being provided at an end of the casing.

Abstract: A reagent composition for the quantitative analysis of inorganic phosphorus, composted of xanthosine, purine nucleoside phosphorylase, xanthine oxidase and a color-former. The color-former is a precursor for forming a dye in the presence of hydrogen peroxide and peroxidase. The reagent composition of the invention is improved in storage stability and has a wider determination range. Also provided is a dry analysis element composed of reagent layer containing the inventive reagent composition.

Abstract: An analytical element for whole blood which comprises a blood cell-separating layer having a volume smaller than the upper limit of the diffused volume of a whole blood sample having a hematocrit value of 70% provided on a porous layer, and a method of measuring an analyte which comprises spotting a whole blood sample onto the above analytical element removing the blood cell-separating layer after blood plasma portion of the sample is diffused into the porous layer, supplying a fixed amount of measuring reagent solution having a diffused area smaller than the diffused area of the blood plasma to measure the analyte. According to the invention, the analytical error caused by scattering of hematocrit values is removed, and analysis can be conducted in a high accuracy.

Abstract: A biochemical analysis apparatus comprises a movement device which moves analysis media containing a reagent or an electrochemical sensor, which will interact with a specific biochemical substance contained in liquid samples and give rise to changes in the analysis media, along a movement path connecting an introducing section and an ejecting section. While the analysis media are present in the movement path, a measurement device measures changes which have occurred in analysis media. A reading device reads information about correction values, which are to be used in order to correct a calibration curve so that it becomes suitable for analysis media used in analyses, from a correction value recording medium. A correction device corrects the calibration curve on the basis of the correction values.

Abstract: An ion-selective electrode for measuring carbonate concentration comprising a conductive metal layer, a halide of said conductive metal layer, a carbonate ion-selective layer containing ion carrier, and a buffer layer containing a hydrophilic polymer binder and a buffer laminated in this order on an electrically insulating support, and a pair of the above electrodes.It is characterized by not having the electrolyte layer containing hydrophilic polymer binder, having the possibility of degradation of the electrolyte layer by the absorption of moisture being extremely little, and having a good stability in the course of time. In the electrode of the invention, the ion-selective layer comprised of hydrophobic organic material is directly laminated on the metal halide layer, the adhesive strength between the metal halide layer and the ion-selective layer is sufficient, the strength of the ion-selective layer is sufficiently great, and which is stable.

Abstract: A device for measuring the activity of carbonate ions and hydrogen ions comprises a carbonate ion selective electrode pair and a hydrogen ion selective electrode pair. Each ion selective electrode comprises a metal layer, metal halide layer and ion selective layer superposed in this order. A porous bridge is disposed so as to achieve a liquid junction between the ion selective electrodes of each electrode pair.