Patent ID: 7166476

Claim:
An agglutination immunoassay for determining the presence and/or amount of an antigenic substance in a sample, which comprises allowing an antigenic substance in a sample to bind to insoluble carrier particles carrying substantially neither antigens nor antibodies thereon, and allowing an antibody or an antibody complex which reacts specifically to the antigenic substance to bind to the antigenic substance to give a selective agglutination of the insoluble carrier particles in the presence of a compound having a group represented by formula (I), wherein n is an integer of 1 to 6, and R 1 , R 2 and R 3 are the same or different, and independently represent hydrogen, substituted or unsubstituted alkyl having 1 to 6 carbon atoms, and measuring the degree of selective agglutination of the insoluble carrier particles, which indicates the presence and/or amount of antigenic substance in the sample.