To obtain a bound substance comprising lumisome containing a specific acridinium ester, detecting an analyte in a liquid sample (a specifically coupled pair of a ligand and an antiligand) and useful in luminescent assay.
An acridinium ester of the formula [R1 is a 0-20 hetero atoms- containing alkyl, alkenyl, alkynyl, aryl, aralkyl; R2, R3, R5, R7 are each H, amino, an alkoxy, hydroxyl; R4 and R8 are each H, an alkyl, an alkenyl, an alkynyl, an aralkyl, an alkoxy, X is an anion, R6 is -R-I(n), Q-R-I(n) (R is the same as R1; Q is an ionizable group such as O, S, NH or -C=O; n is 1-20) bonding to at least one of molecule having biological activity, for example, 2',6'-dimethyl-4'-[N-7-(1,3-disulfonaphthalenyl)carbamoyl]phenyl 10methyl- acridinium-9-carboxylate bromide.
YUURII PIRAN