Binding of DNA to pure silicon dioxide involving formation of hydrogen bonds by disruption of the hydration shell of DNA using chaotropic agents can be easily reversed with water or buffers of low ionic strength. When powdered glass was used instead of pure silicon dioxide the binding of DNA to glass was less easily reversed. DNA bound to glass permits digestion by restriction enzyme, ligation and transformation. The method opens up the possibility of enhancing transformation efficiency especially for DNA digests containing more than two pieces.