Abstract: Novel symmetric, uniformly symmetric and asymmetric 10,10?-substituted-9,9?-biacridines and the synthesis of such symmetric, uniformly symmetric and asymmetric 10,10?-substituted-9,9?-biacridine molecules and their derivatives is disclosed. These molecules are shown to produce light by luminescence in the presence of signals. These symmetric, uniformly symmetric or asymmetric 10,10?-substituted-9,9?-biacridines are used alone or attached to haptens or macromolecules and are utilized as labels in the preparation of iluminescent homogeneous and heterogeneous assays. They are also used in conjunction with other label molecules to produce multiple analyte assays.