Patent ID: 7785904

Claim:
A reagent for the detection or quantification of an analyte comprising a hydrophilic, high quantum yield acridinium sulfonamide compound attached to an analyte, an analyte analog, or a binding molecule for an analyte; wherein the acridinium sulfonamide compound comprises a sulfonamide linkage at C-9 position of the acridinium ring and an electron-donating functional groups of the form —OR*, where R* is a group comprising a sulfopropyl moiety or ethylene glycol moieties, or a combination thereof, at the C-2 and/or the C-7 position of the acridinium ring, wherein the high quantum yield acridinium sulfonamide compound has a relative quantum light yield greater than 1 as compared with a corresponding acridinium sulfonamide compound without electron-donating functional groups at the C-2 and/or the C-7 position of the acridinium ring.