The present invention concerns methods and compositions for making and using bioactive assemblies of defined compositions, which may have multiple functionalities and/or binding specificities. In particular embodiments, the bioactive assembly is formed using dock-and-lock (DNL) methodology, which takes advantage of the specific binding interaction between dimerization and docking domains (DDD) and anchoring domains (AD) to form the assembly. In various embodiments, one or more effectors may be attached to a DDD or AD sequence. Complementary AD or DDD sequences may be attached to an adaptor module that forms the core of the bioactive assembly, allowing formation of the assembly through the specific DDD/AD binding interactions. Such assemblies may be attached to a wide variety of effector moieties for treatment, detection and/or diagnosis of a disease, pathogen infection or other medical or veterinary condition.