Immunochromatographic kit and method for detecting mycobacterium tuberculosis

Abstract

An object of the present invention is to provide an immunochromatographic kit and a method, which are capable of detecting Mycobacterium tuberculosis with high-sensitivity and specificity. According to the present invention, an immunochromatographic kit for detecting Mycobacterium tuberculosis is provided, the kit including: a label substance modified with a first antibody against lipoarabinomannan; a porous carrier having a reaction site holding a second antibody against lipoarabinomannan; a compound containing silver; and a reducing agent reducing silver ions, in which at least one of the first antibody or the second antibody is a monoclonal antibody.

What is claimed is: 
     
         1 . An immunochromatographic kit for detecting  Mycobacterium tuberculosis , the kit comprising:
 a label substance modified with a first antibody against lipoarabinomannan;   a porous carrier having a reaction site holding a second antibody against lipoarabinomannan;   a compound containing silver; and   a reducing agent reducing silver ions,   wherein at least one of the first antibody or the second antibody is a monoclonal antibody.   
     
     
         2 . The immunochromatographic kit according to  claim 1 , wherein at least one of the first antibody or the second antibody is a monoclonal antibody that recognizes a 5-deoxy-5-methylthio-xylofuranose structure of lipoarabinomannan. 
     
     
         3 . The immunochromatographic kit according to  claim 1 , wherein both of the first antibody and the second antibody are monoclonal antibodies. 
     
     
         4 . The immunochromatographic kit according to  claim 1 , wherein the label substance is a metal particle. 
     
     
         5 . The immunochromatographic kit according to  claim 1 , wherein the label substance is gold, silver, platinum, or a compound thereof. 
     
     
         6 . The immunochromatographic kit according to  claim 1 , wherein an average particle size of the label substance 1 nm to 500 nm. 
     
     
         7 . The immunochromatographic kit according to  claim 1 , wherein the compound containing silver is silver nitrate. 
     
     
         8 . The immunochromatographic kit according to  claim 1 , wherein the reducing agent reducing silver ions is Fe 2+ . 
     
     
         9 . The immunochromatographic kit according to  claim 1 , wherein the porous carrier is a nitrocellulose carrier. 
     
     
         10 . The immunochromatographic kit according to  claim 1 , further comprising a coloring reagent for detecting the reducing agent reducing silver ions. 
     
     
         11 . The immunochromatographic kit according to  claim 10 , wherein the coloring reagent is a compound that reacts with ions and develops color. 
     
     
         12 . The immunochromatographic kit according to  claim 10 , wherein the coloring reagent is a compound that reacts with Fe 2+  ions and develops color. 
     
     
         13 . The immunochromatographic kit according to  claim 10 , wherein the coloring reagent is a compound having a phenanthroline skeleton. 
     
     
         14 . The immunochromatographic kit according to  claim 10 , wherein the coloring reagent is a compound that reacts with H +  ions and develops color. 
     
     
         15 . The immunochromatographic kit according to  claim 10 , wherein the coloring reagent is carried by the porous carrier. 
     
     
         16 . The immunochromatographic kit according to  claim 1 , further comprising a housing case including the porous carrier having the reaction site, the compound containing silver, and the reducing agent reducing silver ions. 
     
     
         17 . The immunochromatographic kit according to  claim 1 , further comprising:
 pots each including a tearable member,   wherein the compound containing silver and the reducing agent reducing silver ions are respectively sealed in the pots.   
     
     
         18 . A method for detecting  Mycobacterium tuberculosis , the method comprising:
 a step of spreading a complex body of lipoarabinomannan in a specimen and a label substance modified with a first antibody against lipoarabinomannan on a porous carrier having a reaction site holding a second antibody against lipoarabinomannan;   a step of trapping the complex body at the reaction site; and   a step of amplifying the label substance of the complex body trapped at the reaction site using a compound containing silver and a reducing agent reducing silver ions,   wherein at least one of the first antibody or the second antibody is a monoclonal antibody.   
     
     
         19 . The method for detecting  Mycobacterium tuberculosis  according to  claim 18 , wherein at least one of the first antibody or the second antibody is a monoclonal antibody that recognizes a 5-deoxy-5-methylthio-xylofuranose structure of lipoarabinomannan. 
     
     
         20 . The method for detecting  Mycobacterium tuberculosis  according to  claim 18 , the method further comprising detecting a label substance having an average particle size of equal to or more than 1 μm and equal to or less than 20 μm in a case of detection.