The encapsulation of small DNA molecules was attempted in pure silica and i
n hybrid polyvinyl alcohol-silica gels. The materials which were obtained w
ere examined by nitrogen adsorption, and by Si-29 and P-31 NMR spectroscopy
. The extraction of the DNA molecules from the gels was examined in a buffe
r aqueous solution as well as in an acidic medium. The results suggested th
at the DNA molecules remained trapped inside the gels due to a permanent bo
nding to the gel network. (C) 2001 Kluwer Academic Publishers.