Patent ID: 7226777
Filing Date: 2007-06-05
Classification: G01N

Abstract:
1. A turbidimetric immunoassay for quantifying a concentration of an analyte in a sample solution by mixing the sample solution containing an antigen as the analyte with a reagent containing an antibody that specifically binds to said analyte and detecting signals representing turbidity caused by an antigen-antibody complex produced by said specific binding reaction, said turbidimetric immunoassay comprising the steps of: (1) mixing a plurality of solutions with different known concentrations of analyte and said reagent, respectively, to give a plurality of mixed solutions with different known concentrations of analyte; (2) measuring the turbidity levels of said plurality of mixed solutions over time; (3) determining for each said mixed solutions, the maximum value of said measured turbidity levels (S (4) creating a first calibration curve indicating a first correlation between said known concentrations of analyte and the turbidity levels S(T) detected in said step (3), and a second calibration curve indicating a second correlation between said maximum values of said measured turbidity levels (S wherein said second calibration curve has the maximum value of said S (5) after step (4), mixing said sample solution and said reagent to give a mixed sample solution; (6) measuring the turbidity levels of said mixed sample solution over time; (7) detecting for said mixed sample solution, the maximum value of the turbidity levels measured in said step (6) (Ss (8) comparing said Ts (9) when said Ts (10) when said Ts