METHOD OF QUICKLY DETECTING ANTIGEN USING FLUORESCENCE CORRELATION SPECTROSCOPY OR FLUORESCENCE CROSS-CORRELATION SPECTROSCOPY

摘要

In detecting an antigen by using the fluorescence correlation spectroscopy (FCS) or the fluorescence cross-correlation spectroscopy (FCCS), it is intended to provide a method of quickly detecting the concentration of an arbitrary antigen in an antigen sample without resorting to stepwise examination on the concentration ratio of a detection reagent to the antigen to be detected, particularly in the case where the antigen concentration in the sample is unknown. A method of detecting an antigen by FCS or FCCS with the use of a fluorescent labeled complete antibody targeting an epitope of the antigen to be detected or a fluorescent labeled antibody fragment, which has been fluorescent labeled, and a non- fluorescent labeled complete antibody targeting another epitope of the above-described antigen or a fluorescent labeled complete antibody or a fluorescent labeled antibody fragment, which has been fluorescent labeled, as detection reagents, which comprises preparing a system (1) to which the detection reagents are exclusively added and another system (2) to which an antigen enabling the achievement of the maximum concentration of a trimer and the detection reagents are added, conducting fluorescent analysis, and then quickly detecting the presence or absence of the antigen in the sample based on the presence or absence of a trimer detection signal from a detector in the cases (1) and (2).