Abstract: This invention relates to novel reagent conjugates and a novel multi-step process for delivering active compounds to target analytes of interest in a patient for diagnostic and therapeutic purposes. According to the process, two novel reagents are bound to each other by linkage of the sequence-specific components they contain. The first reagent, which is comprised of a target recognition component and a first sequence-specific component, is introduced into the patient and allowed to achieve maximal localization on the target cells. The second reagent, which is comprised of an active compound component and a second sequence-specific component is then introduced into the patient, thereby forming a complex with the first reagent via the recognition and binding of the sequence-specific components of the two reagents to form the reagent conjugate of the invention. The active compound component is thereby efficiently and specifically delivered to the target analyte.