The 3’-Thiol-Modifier S-S CPG supports are used to introduce 3’-thiol linkages with three and six atom spacers into oligonucleotides. 3’-Dithiol Serinol CPG is used to introduce a dithiol group at the 3’-terminus. In conjunction with Dithiol Serinol Phosphoramidite, it is simple to produce oligonucleotides with multiple thiol groups at the 3’ terminus, which is ideal for conjugation to gold surfaces. With Glyceryl CPG the 3’-terminus of an oligonucleotide is readily oxidized by sodium periodate to form a 3’-phosphoglycaldehyde. The aldehyde may be further oxidized to the corresponding carboxylic acid. Either the aldehyde or the carboxylate may be used for subsequent conjugation to amine-containing products.
Coupling: To avoid oxidative cleavage of the disulfide linkage, all oxidation steps should use 0.02M Iodine solution.
Deprotection: After normal deprotection, the disulfide can be cleaved at room temperature in 30 minutes with 100 mM DTT pH 8.3 - 8.5 in the buffer of your choice.