Test reagent, and method for measuring analyte in test sample using same
Object: To provide a test reagent for the analyte in a test sample, utilizing the level of agglutination of a particle suspension which suspend insoluble carrier particles carrying a substance for capturing the analyte as an indicator, which reagent does not undergo self-agglutination during storage, and which non-specific agglutination rarely occurs during measurement, as well as to provide a method for the analyte to be measured in a test sample. Means for Solution: The test reagent for the analyte comprises at least a Solution A which is a buffer solution having an electric conductivity of not less than 30 ms/cm; and a Solution B having an electric conductivity of not more than 6.5 ms/cm, the Solution B being a particle suspension which suspends particles which are insoluble carrier particles carrying a substance for capturing the analyte.
1. A method of preparing a test reagent for measuring an analyte, said method comprising:
mixing
1) a Solution A having an electric conductivity of not less than 30 ms/cm, said Solution A being a buffer solution, and
2) a Solution B having an electric conductivity of not more than 6.5 ms/cm, said Solution B being a particle suspension which suspends insoluble carrier particles carrying thereon a substance for capturing the analyte.
2. The method according to claim 1 , wherein said Solution A has an electric conductivity of not more than 200 ms/cm.
3. The method according to claim 1 or 2 , wherein said substance for capturing the substance to be measured is an antibody or an antigen-binding fragment thereof, or an antigen.
4. The method according to claim 1 , wherein said insoluble carrier particles are latex particles.
5. The method according to claim 4 , wherein said latex particles are polystyrene latex particles.
6. A method of measuring an analyte in a test sample, said method comprising:
mixing
a Solution A having an electric conductivity of not less than 30 ms/cm, said Solution A being a buffer solution,
a Solution B having an electric conductivity of not more than 6.5 ms/cm, said Solution B being a particle suspension which suspends insoluble carrier particles carrying thereon a substance for capturing the analyte, and
said test sample; and
measuring the analyte in the test sample by the level of agglutination of the particles in the obtained mixture;
wherein at least said Solution A and said Solution B are mixed immediately before the start of the measuring operation.
7. The measuring method according to claim 6 , wherein said test sample is urine, spinal fluid or feces.
8. The measuring method according to claim 6 , wherein said test sample is blood, serum or blood plasma.
9. A test reagent kit comprising a Solution A having an electric conductivity of not less than 30 ms/cm, said Solution A being a buffer solution; and a Solution B having an electric conductivity of not more than 6.5 ms/cm, said Solution B being a particle suspension which suspends insoluble carrier particles carrying thereon a substance for capturing the analyte.
10. The test reagent kit according to claim 9 , wherein said Solution A has an electric conductivity of not more than 200 ms/cm.
11. The test reagent kit according to claim 9 , wherein said substance for capturing the substance to be measured is an antibody or an antigen-binding fragment thereof, or an antigen.
12. The test reagent kit according to claim 9 , wherein said insoluble carrier particles are latex particles.
13. The test reagent kit according to claim 12 , wherein said latex particles are polystyrene latex particles.
14. A test reagent for measuring an analyte, said test reagent obtained by the method according to claim 1 .