Amination of polystyrene microwells: application to the covalent grafting of DNA probes for hybridization assays.

Amine functionalization of polystyrene microwells for covalent binding of DNA is described. Polystyrene support was first carboxylated by permanganate oxidation in diluted sulfuric acid. These functions were activated with water-soluble carbodiimide and grafted with N-methyl-1,3-propane diamine to introduce a free secondary amino group on the support. The samples were characterized by X-ray photoelectron spectroscopy and radiochemical assay. The conditions for covalent linkage of secondary amine on polystyrene microwells were optimized. Functionalized supports were used for covalent binding of a DNA capture probe for the detection of human cytomegalovirus in a sandwich hybridization assay. Sensitivity of the assay compared very well with a commercially available surface, Covalink-NH, microwell plate obtained by electromagnetic irradiation.