Abstract: The present invention relates to a device for preparing assay samples using a number of microscope slides. Each slide has a number of assay reaction surface locations spaced on the planar surface of the slide. In preferred embodiments, the device comprises, in part, a microscope slide holder that has the exterior dimensions of a SBS standard microplate, such as a 96 well plate. The device accepts conventional microscope slides equipped with sixteen microarray surfaces spaced nine millimeters apart on center, or four for a 96 well plate. Individual chamber plates are placed on top of the slides, creating an individual well above each assay reaction surface location. In preferred embodiments, each assay reaction surface location can comprise a microarray of multiple reactive sites. Thus, parallel processing can be done of samples for genomic or proteomic profiling.