DNA-SURFACTANT COMPLEXES IN ORGANIC MEDIA

V.G.Sergeyev, O.A.Pyshkina, M.O.Gallyamov, I.V.Yaminsky, A.B.Zezin, V.A.Kabanov

A linear DNA can be dissolved in nonaqueous low-polar organic solvent by forming complexes between DNA and cationic surfactants. The data of high-rate sedimentation, UV-spectrometcic and circular dichroism measurements show that the DNA complexes with surfactant in chloroform, heptane and cyclohexane are individual components with a 1:1 stoichiometry. The DNA molecules passing to the organic phase retain a double-stranded helix conformation. By means of scanning tunneling and atomic-force microscopy it was found that DNA-surfactant complexes exist in compact toroidal conformation. It was demonstrated that such complexes can be transferred through water/organic phase boundaries.