Abstract: An object of the present invention is to enable to accurately quantify HBs antigen in the samples for which measured values are low or false-negative results by the conventional assaying method of HBs antigen. In the method of assaying HBs antigen according to the present invention, at least one inner capture probe that binds to a first inner region peptide consisting of 26th to 80th amino acid residues of HBs antigen and at least one outer capture probe that binds to a second outer region peptide consisting of 98th to 156th amino acid residues of HBs antigen are used as capture probes; and at least one inner detection probe which binds to the first inner region and at least one outer detection probe which binds to the second outer region are used as detection probes.

Abstract: The purpose is to produce, with high reproducibility, a complex of labeled probes and a carrier, said complex being to be used for detecting and measuring a target substance to be measured with high sensitivity and high stability. The means for accomplishing the purpose is that a label is bound to a probe-water soluble carrier conjugate using specific binding of an avidin compound such as avidin, streptavidin, etc. to biotin, and the binding of the avidin compound to the probe is performed before the binding to the carrier. Namely, after conjugating the avidin compound to a substance which is capable of binding to the target substance, the conjugate is bound to a high-molecule water-soluble carrier to produce a complex of the avidinized probes and the water-soluble carrier. Then the complex of the avidinized probes and the water-soluble carrier is mixed with a biotinylated label.

Abstract: Disclosed are an HCV gene having higher replication efficiency and higher reinfection efficiency than the known HCV gene of genotype 1b, an RNA replicon having this gene, a cell infected with this RNA replicon, which cell allows replication of HCV, and an HCV particle. The hepatitis C virus gene encodes an amino acid sequence wherein the 979th amino acid is threonine; the 1804th amino acid is leucine; and the 1966th amino acid is lysine. An HCV gene which can propagate in vitro and has higher replication efficiency and higher reinfection efficiency than the known HCV gene of genotype 1b was provided.

Abstract: An HCV/GBV-B chimeric virus which maintains the replication function of HCV and is capable of infecting tamarin is disclosed in order to construct an HCV animal model which can be used as a development or evaluation system for therapeutic agents for HCV. The HCV/GBV-B chimeric RNA comprises an RNA of hepatitis C virus and an RNA of GB virus-B, wherein the RNA of hepatitis C virus comprises an RNA encoding leucine at the 1804th position and lysine at the 1966th position in the amino acid sequence of the polyprotein of hepatitis C virus.

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: Disclosed is a novel high-sensitive ProGRP measurement method, which is free from problems such as the fluctuations in measurement values and the operational constraints (e.g., the constraints on the handling of a sample). Specifically disclosed is a method for the measurement of a gastrin-releasing peptide precursor and/or a digested product thereof using at least two different antibodies each of which can recognize an epitope represented by the amino acid sequence consisting of amino acid 47 to amino acid 68 of the amino acid sequence set forth in SEQ ID NO:1. The method can detect a ProGRP or a digested product thereof in a refrigerated sample within a shorter period, by using the sample in a smaller amount, and with a higher degree of detective sensitivity, compared with the conventional methods.

Abstract: A method of treating samples containing hepatitis C virus (HCV) which method comprises treating HCV-containing samples with a treating agent containing (1) an acidifying agent, and (2) a protein-denaturing agent, or an amphoteric surfactant or a cationic surfactant having both a straight chain alkyl group of 10 or more carbon atoms and a tertiary amine or a quaternary ammonium salt in the same molecule, to effect the release of the HCV antigen and the inactivation of antibodies that bind to the HCV antigen, and the like.

Abstract: The purpose is to produce, with high reproducibility, a complex of labeled probes and a carrier, said complex being to be used for detecting and measuring a target substance to be measured with high sensitivity and high stability. The means for accomplishing the purpose is that a label is bound to a probe-water soluble carrier conjugate using specific binding of an avidin compound such as avidin, streptavidin, etc. to biotin, and the binding of the avidin compound to the probe is performed before the binding to the carrier. Namely, after conjugating the avidin compound to a substance which is capable of binding to the target substance, the conjugate is bound to a high-molecule water-soluble carrier to produce a complex of the avidinized probes and the water-soluble carrier. Then the complex of the avidinized probes and the water-soluble carrier is mixed with a biotinylated label.

Abstract: Disclosed are an HCV gene having higher replication efficiency and higher reinfection efficiency than the known HCV gene of genotype 1b, an RNA replicon having this gene, a cell infected with this RNA replicon, which cell allows replication of HCV, and an HCV particle. The hepatitis C virus gene encodes an amino acid sequence wherein the 979th amino acid is threonine; the 1804th amino acid is leucine; and the 1966th amino acid is lysine. An HCV gene which can propagate in vitro and has higher replication efficiency and higher reinfection efficiency than the known HCV gene of genotype 1b was provided.

Abstract: There is provided a HBV precore protein having an ability of forming particles, and a means for determining it. A novel HBV precore protein that forms the virus (like) particles of HBV was identified. The present invention provides this novel HBV precore protein. Furthermore, there are provided core-like particles and virus-like particles formed by this HBV precore protein. These virus-like particles can be used for vaccines and therapeutic agents. The present invention also provides a method of determining the HBV precore protein and a method of determining the anti-HBV precore protein antibody.

Abstract: Disclosed is a novel method for determination of ProGRP which is free from problems such as the dispersion in the values of measurements and operational constraints such as handling of a test sample. A method for the determination of a gastrin-releasing peptide precursor or a digest thereof using at least two different antibodies each of which can recognize a peptide comprising the partial amino acid sequence starting from amino acid residue 40 and ended at amino acid residue 75 in the amino acid sequence depicted in SEQ ID NO:1; and a method for the determination of a gastrin-releasing peptide precursor and/or a digest thereof using at least two different antibodies each of which can recognize a peptide comprising the partial amino acid sequence starting from amino acid residue 40 and ended at amino acid residue 79 in the amino acid sequence depicted in SEQ ID NO:1.

Abstract: The present invention relates to a method of concentrating low molecular weight peptides in the supernatant of serum-free cultured cells, said method comprising allowing the peptides to bind to a strong cation exchanger under an acid condition, and eluting them under an alkali condition to concentrate the peptide. Furthermore, peptides having the amino acid sequence as set forth in SEQ ID NO: 1 or 2, and a method of screening cancer markers using antibody to these peptides, are disclosed.

Abstract: The present invention relates to a method of concentrating low molecular weight peptides in the supernatant of serum-free cultured cells, said method comprising allowing the peptides to bind to a strong cation exchanger under an acid condition, and eluting them under an alkali condition to concentrate the peptide. Furthermore, peptides having the amino acid sequence as set forth in SEQ ID NO: 1 or 2, and a method of screening cancer markers using antibody to these peptides, are disclosed.

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: Disclosed is a novel high-sensitive ProGRP measurement method, which is free from problems such as the fluctuations in measurement values and the operational constraints (e.g., the constraints on the handling of a sample). Specifically disclosed is a method for the measurement of a gastrin-releasing peptide precursor and/or a digested product thereof using at least two different antibodies each of which can recognize an epitope represented by the amino acid sequence consisting of amino acid 47 to amino acid 68 of the amino acid sequence set forth in SEQ ID NO:1. The method can detect a ProGRP or a digested product thereof in a refrigerated sample within a shorter period, by using the sample in a smaller amount, and with a higher degree of detective sensitivity, compared with the conventional methods.

Abstract: There is provided a HBV precore protein having an ability of forming particles, and a means for determining it. A novel HBV precore protein that forms the virus (like) particles of HBV was identified. The present invention provides this novel HBV precore protein. Furthermore, there are provided core-like particles and virus-like particles formed by this HBV precore protein. These virus-like particles can be used for vaccines and therapeutic agents. The present invention also provides a method of determining the HBV precore protein and a method of determining the anti-HBV precore protein antibody.

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: To provide a blocked enzyme marker complex that can be used for the high sensitivity the highly sensitive detection of antigens, proteins, etc. existing infinitesimally in the living body. There is provided a blocked enzyme probe complex comprising a block composed of, bound via an enzyme or a linker, combos of a carrier of two or more molecules of 20,000 to 4,000,000 molecular weight and an enzyme, wherein a probe molecule is bound to the enzyme or the carrier.

Abstract: A method of treating samples containing hepatitis C virus (HCV) which method comprises treating HCV-containing samples with a treating agent containing (1) an acidifying agent, and (2) a protein-denaturing agent, or an amphoteric surfactant or a cationic surfactant having both a straight chain alkyl group of 10 or more carbon atoms and a tertiary amine or a quaternary ammonium salt in the same molecule, to effect the release of the HCV antigen and the inactivation of antibodies that bind to the HCV antigen, and the like.

Abstract: A Method for detecting hepatitis B virus as well as a kit and a reagent therefor, comprising using a phosphate buffer that specifically binds to hepatitis B virus, for example a monoclonal antibody that specifically binds to a specific site of core-related protein of hepatitis B virus.