END ATTACHMENT OF PHENOL OLIGONUCLEOTIDE CONJUGATES TO DIAZOTIZED CELLULOSE

The synthesis of a novel phosphoramidite reagent with a hexanediol bac kbone is described. This reagent has been used to incorporate a phenol moiety on an oligonucleotide (ODN) directly in the course of its auto mated synthesis. Multiple phenol attachments can be achieved by repeti tive coupling cycles. A simple and rapid immobilization method is desc ribed where phenol-modified ODNs are covalently attached to diazotized cellulose. The binding capacity of the membrane can be modulated, dep ending on the ODN concentration used, to ca. 180 pmol/cm2. There is at least 80% end attachment of the ODN through the phenol group. In addi tion, the phenol residue can be used as a carrier for the radiolabelin g with I-125. The non-nucleosidic hexanediol derivative incorporated a t the 5'-end of the ODN is recognized as a substrate by the T4 polynuc leotide kinase and the terminal hydroxyl group is successfully phospho rylated allowing its P-32 labeling.