Abstract: The present invention provides a method for specifically detecting a Mycobacterium tuberculosis complex-specific secretory protein MPT64 antigen in a biological sample, whereby diagnosis of infection with Mycobacterium tuberculosis is carried out rapidly and safely with higher accuracy than before. An antibody that recognizes an epitope for MPB64 located in any one of amino acid sequences of SEQ ID NOS: 2 to 4, particularly a monoclonal antibody was obtained. Thus, an immunoassay using the antibody, particularly a sandwich immunoassay using first and second antibodies to MPB64, particularly an immunochromatographic assay and an immunochromatographic test strip are provided. A biological sample can be rapidly subjected to the immunoassay without culturing or after culturing for a time before Mycobacterium tuberculosis complex bacteria in the sample substantially start to grow.

Abstract: The present invention provides a method for detecting a virulent strain of influenza virus in a specific, rapid and simple manner, and an assay device therefor. A method for detecting a virulent strain of influenza A virus is provided, which comprises providing a first antibody that is reactive with all influenza A virus subtypes and a second antibody that is not reactive with a virulent strain of influenza A virus but is reactive with all influenza A virus subtypes other than the virulent strain, and conducting an immunoassay to detect an antigen that shows a positive response in a reaction with the first antibody and shows a negative response in a reaction with the second antibody.