Method of immunity examination with insoluble carrier particle and reagent therefor

Abstract

The present invention provides a reagent for an immunoassay comprising insoluble carrier particles which can give the values to be determined with high accuracy and reliability, and can be stored for a long time; an immunoassay using the reagent; and a method for keeping the reagent stable. The present invention provides an immunoassay which comprises carrying out an antigen-antibody reaction using insoluble carrier particles in an aqueous medium comprising a buffer having its buffer capacity in a neutral or alkaline region (except for a carbonate-based buffer) and a carbonic acid compound releasing a bicarbonate ion; a reagent for an immunoassay comprising a buffer having its buffer capacity in a neutral or alkaline region (except for a carbonate-based buffer), a carbonic acid compound releasing bicarbonate ion, and insoluble carrier particles; and a method for keeping the reagent for an immunoassay comprising insoluble carrier particles stable, which comprises allowing insoluble carrier particles to co-exist in an aqueous medium comprising a buffer having its buffer capacity in a neutral or alkaline region (except for a carbonate-based buffer) and a carbonic acid compound releasing a bicarbonate ion.

1 . An immunoassay, which comprises carrying out an antigen-antibody reaction using insoluble carrier particles in an aqueous medium comprising a buffer having its buffer capacity in a neutral or alkaline region (except for a carbonate-based buffer) and a carbonic acid compound releasing a bicarbonate ion.  
     
     
         2 . The immunoassay according to  claim 1 , wherein the carbonic acid compound releasing a bicarbonate ion is an alkali metal compound.  
     
     
         3 . The immunoassay according to  claim 1  or  2 , wherein the concentration of the bicarbonate ion is 0.05 to 500 mmol/L.  
     
     
         4 . The immunoassay according to any of  claims 1  to  3 , wherein the concentration of the buffer having its buffer capacity in a neutral or alkaline region is 0.1 to 500 mmol/L.  
     
     
         5 . The immunoassay according to any of  claims 1  to  4 , wherein the insoluble carrier particles are those which antibodies reactive with substance to be determined are bound to.  
     
     
         6 . The immunoassay according to any of  claims 1  to  4 , wherein the insoluble carrier particles are those which substance to be determined is bound to.  
     
     
         7 . The immunoassay according to any of  claims 1  to  6 , wherein the insoluble carrier particles are latex.  
     
     
         8 . The immunoassay according to any of  claims 1  to  7 , wherein the immunoassay is a nephelometric immunoassay.  
     
     
         9 . A reagent for an immunoassay comprising a buffer having its buffer capacity in a neutral or alkaline region (except for a carbonate-based buffer), a carbonic acid compound releasing a bicarbonate ion and insoluble carrier particles.  
     
     
         10 . The reagent for an immunoassay according to  claim 9 , wherein the buffer having its buffer capacity in a neutral or alkaline region (except for a carbonate-based buffer), the carbonic acid compound releasing a bicarbonate ion and the insoluble carrier particles are comprised in an aqueous medium.  
     
     
         11 . The reagent for an immunoassay according to  claim 9  or  10 , wherein the carbonic acid compound releasing a bicarbonate ion is an alkali metal compound.  
     
     
         12 . The reagent for an immunoassay according to  claim 10  or  11 , wherein the concentration of the bicarbonate ion is 0.05 to 500 mmol/L.  
     
     
         13 . The reagent for an immunoassay according to any of  claims 10  to  12 , wherein the concentration of the buffer having its buffer capacity in a neutral or alkaline region is 0.1 to 500 mmol/L.  
     
     
         14 . The reagent for an immunoassay according to any of  claims 9  to  13 , wherein the insoluble carrier particles are those which antibodies reactive with substance to be determined are bound to.  
     
     
         15 . The reagent for an immunoassay according to any of  claims 9  to  14 , wherein the insoluble carrier particles are latex.  
     
     
         16 . A method for keeping a reagent for an immunoassay comprising insoluble carrier particles stable, wherein the insoluble carrier particles are comprised in an aqueous medium comprising a buffer having its buffer capacity in a neutral or alkaline region (except for a carbonate-based buffer) and a carbonic acid compound releasing a bicarbonate ion.  
     
     
         17 . The method for keeping a reagent for an immunoassay comprising insoluble carrier particles stable according to  claim 16 , wherein the carbonic acid compound releasing a bicarbonate ion is an alkali metal compound.  
     
     
         18 . The method for keeping a reagent for an immunoassay comprising insoluble carrier particles stable according to  claim 16  or  17 , wherein the concentration of the bicarbonate ion is 0.05 to 500 mmol/L.  
     
     
         19 . The method for keeping a reagent for an immunoassay comprising insoluble carrier particles stable according to any of  claims 16  to  18 , wherein the concentration of the buffer having its buffer capacity in a neutral or alkaline region is 0.1 to 500 mmol/L.  
     
     
         20 . The method for keeping a reagent for an immunoassay comprising insoluble carrier particles stable according to any of  claims 16  to  19 , wherein the insoluble carrier particles are those which antibodies reactive with substance to be determined are bound to.  
     
     
         21 . The method for keeping a reagent for an immunoassay comprising insoluble carrier particles stable according to any of  claims 16  to  20 , wherein the insoluble carrier particles are latex.