Covalent immobilization of DNA onto polystyrene microwells: The molecules are only bound at the 5′ end

Carbodiimide-mediated condensation of DNA onto microwells is investigated. DNA is bound onto the microwells by formation of a phosphoramidate bond between the 5′ terminal phosphate group and the microwells. Immobilization of 25 to 30 ng DNA per well is obtained. DNA molecules bound covalently at only the 5′ end are, ideally, perfect for hybridization. The practicability of DNA molecules bound to microwells for hybridization is investigated.