The volume phase transition of DNA and RNA gels

The first order volume phase transitions of DNA gel, RNA/DNA gel and DNA/ magnetic fluid mixtures gel in acetone-water mixtures are described. The phase transition is measured as a function of solvent composition, temperature and pH, and pattern formations on the surface of DNA gels are observed to be shown as 5- and 6-sided honeycomb cells like quasi-crystals. A phenomenological theory which describes size effect on the transition is tentatively demonstrated by considering the surface tension acting on the ionic gel such as DNA, RNA/DNA mixtures and qualitatively compared with the experimental results.