Abstract: A method of assaying a sample with the use of the aggregation reaction of immunological microparticles and an assay kit. The assay is conducted by using microparticles wherein the same or an analog of the analyte and a substance that specifically binds to a substance that can specifically bind to the analyte are both bound to an insoluble carrier. Thus, it becomes possible to conveniently carry out the assay even in the case where the analyte has only a small number of specific binding sites, without especially adding a competitive substance carrying hapten bonded thereto to the reaction system so as to induce simultaneous competition of the target substance and the competitive substance.

Abstract: A method of assaying a sample with the use of the aggregation reaction of immunological microparticles and an assay kit. The assay is conducted by using microparticles wherein the same or an analog of the analyte and a substance that specifically binds to a substance that can specifically bind to the analyte are both bound to an insoluble carrier. Thus, it becomes possible to conveniently carry out the assay even in the case where the analyte has only a small number of specific binding sites, without especially adding a competitive substance carrying hapten bonded thereto to the reaction system so as to induce simultaneous competition of the target substance and the competitive substance.

Abstract: A method for measuring an acrolein adduct present in a sample comprising the steps of: (a) mixing a sample containing the acrolein adduct with a solution comprising an immunoglobulin that specifically recognizes the acrolein adduct; (b) adding to the mixture obtained in the step (a), a solution comprising microparticles to which a substance that specifically binds to the immunoglobulin that specifically recognizes the acrolein adduct and a blocking agent have been bound, and mixing them; and (c) measuring an extent of an agglutination reaction of the microparticles in the mixture obtained in the step (b), wherein the extent of the agglutination reaction being decreased relative to an amount of the acrolein adduct in the sample. The method enables a measurement of an acrolein adduct without requiring a complex operation.

Abstract: A method for determining fibrinogen concentration whereby thrombin or a protease inhibitor having similar activity thereto is added to an undiluted to test sample to convert fibrinogen in the sample to fibrin, and determining a coagulation time fibrinogen is converted in a reaction mixture containing a salt at a high concentration and a reagent therefor. The determination in the presence of a salt at a high concentration permits simplified determination without diluting the test sample.

Abstract: An improved method of a conventional antithrombin III activity determination method, which does not require dilution of a sample and can avoid influence of heparin cofactor II is provided. This method is characterized in that the reaction of a sample with thrombin in the presence of heparin is carried out in the presence of more than 0.2 to 0.9M of a salt, while such a reaction is carried out in the presence of 0.2M of a salt in a conventional method.

Abstract: An accurate, rapid and simple method of determining blood coagulation factor XIII activity and a kit of reagents therefor are provided. A sample and a fibrin precipitation inhibitor are mixed, or a sample, fibrinogen and a fibrin precipitation inhibitor are mixed; a thrombin solution is added; the fibrin coagulation time is measured in the presence of calcium ion; and the coagulation time is compared with the normal coagulation time. The kit for the determination comprises thrombin, calcium ion and a fibrin precipitation inhibitor, and may be combined with fibrinogen.

Abstract: A method for determination of biological activity of AT III which comprises mixing a specimen, AT III free-extrinsic coagulation factor-containing plasma, heparin and a prothrombin time-measuring reagent or a factor X-activating reagent and then measuring a coagulation time, and a reagent and plasma to be used therefor.

Abstract: Blood coagulation factors are stabilized by addition of glycylglycine and/or glycylglycylglycine to blood or plasma in such an amount that they have no effect on a blood coagulation time.

Abstract: A method for determination of biological activity of AT III by measuring coagulating time of blood plasma comprises mixing a specimen having AT III free-extrinsic coagulation factor-containing plasma, heparin and a prothrombin time-measuring reagent or a factor X-activating reagent and then measuring the coagulation time, and a reagent and plasma to be used therefor.

Abstract: Reagent for the measurement of direct bilirubin comprising a buffer solution having a pH range of 3.5 to 4.5 which contains bilirubin oxidase, preferably in the form of a test kit consisting essentially of (i) a buffer solution having a pH range of 3.5 to 4.5, (ii-a) a lyophilized bilirubin oxidase, (ii-b) a buffer solution for dissolving the lyophilized bilirubin oxidase, and (iii) a standard serum containing a prescribed amount of bilirubin, and a method for measurement of direct bilirubin by using the reagent. The reagent and method are useful for diagnosis of various diseases, for example, various hepatic diseases (e.g. jaundice) and cholepathia.