Abstract: This invention relates to devices and to methods, diagnostic reagents and kits embodying such devices for use in ligand/anti-ligand assays and the qualitative or semi-quantitative detection of a substance of interest thereby through use of light or photon detecting systems such as reflectometers, colorimeters, fluorimeters and the human eye. Such devices, methods and kits have applications in the biologic research and medical fileds for assaying drugs, hormones, peptides, proteins, enzymes, nucleic acids, antibodies, haptens, antibiotics, viri, infectious agents, tumor markers and the like, in the laboratory, the physicians' office, the veterinarian's office and the home.