Abstract: A first polynucleotide is formed with a first particular sequence of nucleotides such as by providing a solid-phase support and adding nucleotides to the support. A second polynucleotide is formed in a similar manner with a second particular sequence of nucleotides which are complementary to the nucleotides in the first polynucleotide at first particular ends of the polynucleotides. The first particular ends may be the 3'-ends of the polynucleotides. The polynucleotides are hybridized or annealed at their 3'-ends to form a base-pair complementary stretch between the first and second polynucleotides. A repair synthesis is then provided in the first and second polynucleotides at second ends (such as the 5'-ends) opposite the first particular ends to provide a double-stranded polynucleotide. The repair synthesis may be monitored by labelling the second end (or 5'-end) of one or both of the nucleotides with radioactivity and then subjecting the nucleotides to an enzymatic reaction.

Abstract: A resin support formed from a suitable resin such as polystyrene or a silica gel may be provided by forming an amino resin and by reacting the amino resin with an activated ester of a nucleoside to obtain the dimethoxytrityl resin. To add each successive nucleotide to the resin support, the nucleoside is phosphorylated to provide a monotriazolide. The phosphorylation may be provided by the reaction of a phosphoditriazolide with a 3'-hydroxyl neucleoside. The dimethoxytrityl resin is then hydroxylated to substitute the hydroxyl group for the dimethoxytrityl group in the resin support. The monotriazolide is then reacted with the hydroxylated resin support to provide the dimethoxytrityl resin. This reaction may occur in the presence of a nucleophilic catalyst, such as a catalyst selected from a group consisting of dimethylaminopyridine, N'-methylimidazole and tetrazole.

Abstract: A commercially available resin such as polystyrene is converted into a phthalimidomethyl-resin by treatment with potassium phthalimide. The phthalimidomethyl-resin is converted into an amino resin with hydrazine in ethanol. The amino resin is then combined with an activated ester of a nucleoside to obtain an amide-bonded dimethoxytrityl resin. The activated ester of the nucleoside is obtained by reacting a nucleoside with succinic anhydride in the presence of 4-(dimethylamino) pyridine in pyridine to provide a monosuccinate derivative, which is in turn treated with pentachlorophenol and dicyclohexylcarbodimide in dimethylformamide. Any unreacted amino groups in the amide-bonded dimethoxytrityl resin may be masked and the dimethoxytrityl group may be removed by treatment of the amide-bonded resin with a solution of benzenesulfonic acid to obtain a hydroxylated resin support.