| 摘要 |
Provided is a method for measuring a substance of interest in a test sample rapidly using a small fluorescence detection device that can be used on-site. A method for detecting a substance of interest, i.e., an antigen, using an antibody reagent for antigen-antibody reactions, wherein the antibody reagent comprises a complex of a polypeptide containing an antibody light-chain variable region and a polypeptide containing an antibody heavy-chain variable region, the polypeptide containing the antibody light-chain variable region and/or the polypeptide containing the antibody heavy-chain variable region is labeled with a fluorescent dye, and the antibody reagent for antigen-antibody reactions can detect the antigen, i.e., the substance of interest, by employing a matter that the concentration of the antigen, i.e., the substance of interest, in a liquid phase has a positive or negative correlation with the fluorescence intensity of the fluorescent dye as a measure. The method comprises: carrying out a fluorescence intensity measurement at predetermined intervals after the initiation of an antigen-antibody reaction; comparing fluorescent intensities obtained in the measurements to calculate the amount or ratio of increase in fluorescence or the amount or ratio of decrease in fluorescence with one another; comparing the amount or ratio of increase in fluorescence or the amount or ratio of decrease in fluorescence with a predetermined criterion value; and determining that the substance of interest is present when the amount or ratio of increase in fluorescence is larger than the criterion value or the amount or ratio of decrease in fluorescence is smaller than the criterion value and determined that the substance of interest is absent when the amount or ratio of increase in fluorescence does not become higher than the criterion value or the amount or ratio of decrease in fluorescence does not become smaller than the criterion value within a predetermined determination period. The criterion value is an amount or ratio of increase in fluorescence or an amount or ratio of decrease in fluorescence as measured when the complex is reacted with a substance of interest which is not desired to detect and has the largest concentration for a predetermined determination period. |
