Abstract
A deoxyribohexanucleotide corresponding to a restriction endonuclease (Eco RI) recognition sequence, d-G-A-A-T-T-C, was synthesized by stepwise condensation of mononucleotides using dicyclohexylcarbodiimide (DCC) or 2, 4, 6-triisopropylbenzenesulfonyl chloride (TPS) as the condensing reagent. Protected oligonucleotides were separated by ion-exchange chromatography or gel filtration and the deblocked hexanucleotide was purified by DEAE-cellulose column chromatography in the presence of 7 M urea. The product was characterized by enzymatic hydrolysis and its temperature-absorption profile was measured at high ionic strength.
