US Patent 7122671 Luminescent labelling materials and procedures

A compound for use as a chemiluminescent label in immunoassay comprises an aryl acridinium ester linked to an N-succinimidyl moiety. The compound is conveniently linked to a monoclonal antibody or other protein and is used in a two-site immunoassay for the quantitation of an antigen of interest, by initiation of the luminescent reaction and subsequent measurement of the photonic emission of the immune complex formed during the immunological reaction.