Fusion of restriction termini using synthetic adaptor oligonucleotides.

A method is proposed for linking a DNA fragment possessing a 5' single-stranded extension to one carrying a 3' extension. Synthetic oligonucleotide adaptors can be used to (i) change the site specificity at the termini of a fragment generated by restriction enzyme cleavage and (ii) simultaneously dephosphorylate the extremities of a DNA molecule to prevent recircularisation and allow positive selection for recombinant DNA molecules.