The present work describes a complete and reversible transformation of DNA's properties allowing solubilization in organic solvents and subsequent chemical modifications that are otherwise not possible in an aqueous medium. Organo-soluble DNA (osDNA) moieties are generated by covalently linking a dsDNA fragment to a polyether moiety with a built-in mechanism, rendering the process perfectly reversible and fully controllable. The precise removal of the polyether moiety frees up the initial DNA fragment, unaltered, both in sequence and nature. The solubility of osDNA was confirmed in six organic solvents of decreasing polarity and six types of osDNAs. As a proof of concept, in the context of DNA-encoded library (DEL) technology, an amidation reaction was successfully performed on osDNA in 100% DMSO. The development of osDNA opens up entirely new avenues for any DNA applications that could benefit from working in nonaqueous solutions, including chemical transformations.