the present invention provides a method and reagent composition for attachment of target molecules onto the surface of a substrate , such as microwell plates , tubes , beads , microscope slides , silicon wafers or membranes . in one embodiment , the method and composition are used to immobilize nucleic acid probes onto plastic materials such as microwell plates , e . g ., for use in hybridization assays . in a preferred embodiment , the method and composition are adapted for use with substantially flat surfaces , such as those provided by microscope slides and other plastic , silicon hydride , or organosilane - pretreated glass or silicone slide support surfaces . the reagent composition can then be used to attach a target molecule such as a biomolecule which in turn can be used for specific binding reactions .