Abstract: Disclosed is a novel method showing a higher detection sensitivity for hepatitis B virus genotype D than those of known methods. A method of immunoassay of hepatitis B virus core-related antigen uses, as an antibody to be used for the immunoassay, a monoclonal antibody that specifically binds to at least one kind of core-related antigen of hepatitis B virus genotype D, or an antigen-binding fragment thereof, wherein an epitope of the monoclonal antibody or the antigen-binding fragment thereof is a region included in the amino acid sequence from position 31 to 48 of SEQ ID NO:3.

Abstract: Disclosed is a highly sensitive assay method and assay kit for HBsAg, which do not require treatment with a strong acid or alkali in the sample pretreatment, and which is less susceptible to influences by the autoantibodies. The assay method for hepatitis B virus s antigen in a sample separated from a living body includes: a pretreatment step of mixing a sample with a pretreatment reagent containing a reducing agent, to reduce hepatitis B virus s antigen; and an immunoassay step of subjecting the pretreated sample to an immunoassay of hepatitis B virus s antigen using at least one antibody or antigen-binding fragment thereof capable of antigen-antibody reaction with a reduced peptide composed of the amino acids at positions 98 to 179 of hepatitis B virus s antigen.

Abstract: Disclosed are a measurement method and a measurement reagent for thyroglobulin, which measurement method and measurement reagent enable more accurate measurement of the thyroglobulin level by a single test without being influenced by interference of anti-thyroglobulin antibody, and which measurement method and measurement reagent allow use of even an antibody less resistant to an acidifier and/or a surfactant in an immunoassay. A method of measuring, by an immunoassay, thyroglobulin in a sample separated from a living body includes a pretreatment step of mixing the sample separated from the living body with a pretreatment liquid containing an alkaline substance.

Abstract: Disclosed is a highly sensitive assay method and assay kit for HBsAg, which do not require treatment with a strong acid or alkali in the sample pretreatment, and which is less susceptible to influences by the autoantibodies. The assay method for hepatitis B virus s antigen in a sample separated from a living body includes: a pretreatment step of mixing a sample with a pretreatment reagent containing a reducing agent, to reduce hepatitis B virus s antigen; and an immunoassay step of subjecting the pretreated sample to an immunoassay of hepatitis B virus s antigen using at least one antibody or antigen-binding fragment thereof capable of antigen-antibody reaction with a reduced peptide composed of the amino acids at positions 98 to 179 of hepatitis B virus s antigen.

Abstract: [PROBLEMS] To provide a probe useful in the detection of HBV or HBs antigen by which an escape mutant of hepatitis B virus (HBV) possibly occurring in a specimen can be detected; and a method of using the same. [MEANS FOR SOLVING PROBLEMS] A probe capable of recognizing an epitope located on a peptide comprising the amino acid sequence of SEQ ID NO:1; and a method of detecting hepatitis B virus or hepatitis B virus s antigen by using this probe.

Abstract: A method for treating a virus-containing sample, characterized by treatment of a virus-containing sample with a treatment solution containing (1) an anionic surfactant and (2) an amphoteric surfactant, nonionic surfactant or protein denaturant; a virus assay method using said treating method; a method for treating a virus-containing sample, characterized by treatment of a virus-containing sample with a treatment solution containing (1) a chaotropic ion and (2) an acidifying agent; a virus assay method using said treating method; a virus assay method, characterized in that a virus antigen and a virus antibody are measured based on their binding to their probe in the presence of a surfactant with an alkyl group of 10 or more carbon atoms and a secondary, tertiary or quaternary amine, or a nonionic surfactant, or of both of them; and a monoclonal antibody and a hybridoma producing the same for carrying out said method.

Abstract: To provide a method for detection or quantification of hepatitis B virus (HBV) antigens in serum and a simple and highly user-friendly method for sample treatment for use in the detection or quantification thereof. The method for treatment of a sample containing hepatitis B virus (HBV) is characterized in that release of HBV antigens and disruption of antibodies that bind to HBV antigens are carried out by treating a sample containing HBV with a treatment agent containing (1) an acidifying agent and (2) a protein denaturant or an amphoteric surfactant or cationic surfactant having an alkyl group and a tertiary amine or a quaternary ammonium salt within a molecule.

Abstract: A method for treating a virus-containing sample, characterized by treatment of a virus-containing sample with a treatment solution containing (1) an anionic surfactant and (2) an amphoteric surfactant, nonionic surfactant or protein denaturant; a virus assay method using said treating method; a method for treating a virus-containing sample, characterized by treatment of a virus-containing sample with a treatment solution containing (1) a chaotropic ion and (2) an acidifying agent; a virus assay method using said treating method; a virus assay method, characterized in that a virus antigen and a virus antibody are measured based on their binding to their probe in the presence of a surfactant with an alkyl group of 10 or more carbon atoms and a secondary, tertiary or quaternary amine, or a nonionic surfactant, or of both of them; and a monoclonal antibody and a hybridoma producing the same for carrying out said method.

Abstract: The present invention provides a hepatitis C virus gene, a replicon RNA derived from the gene, a replicon-replicating cell into which the replicon RNA is introduced, and a method for screening a drug using the replicon-replicating cell.

Abstract: To provide a method for detection or quantification of hepatitis B virus (HBV) antigens in serum and a simple and highly user-friendly method for sample treatment for use in the detection or quantification thereof. The method for treatment of a sample containing hepatitis B virus (HBV) is characterized in that release of HBV antigens and disruption of antibodies that bind to HBV antigens are carried out by treating a sample containing HBV with a treatment agent containing (1) an acidifying agent and (2) a protein denaturant or an amphoteric surfactant or cationic surfactant having an alkyl group and a tertiary amine or a quaternary ammonium salt within a molecule.

Abstract: [PROBLEMS] To provide a probe useful in the detection of HBV or HBs antigen by which an escape mutant of hepatitis B virus (HBV) possibly occurring in a specimen can be detected; and a method of using the same. [MEANS FOR SOLVING PROBLEMS]A probe capable of recognizing an epitope located on a peptide comprising the amino acid sequence of SEQ ID NO:1; and a method of detecting hepatitis B virus or hepatitis B virus s antigen by using this probe.

Abstract: A method for measurement of the hepatitis C virus (HCV) characterized by measuring HCV core antigen and HCV core antibody by their binding with probes in the presence of an anionic surfactant or a non-ionic surfactant, or both.

Abstract: A method for measurement of the hepatitis C virus (HCV) characterized by measuring HCV core antigen and HCV core antibody by their binding with probes in the presence of an anionic surfactant or a non-ionic surfactant, or both.