Preferentially, the present polysubstituted aryl acridinium ester compounds should be as described above with the following substituents; R1 is a methyl group; R2, R3, R5, and R7 are hydrogen; R4 and R8 are a methyl or methoxyl group, R10 is an N-succinimidyl oxycarbonyl group attached directly to the para-position of the phenoxy ring, and X is CH3 SO4 -.