Poly(N-isopropylacrylamide) Carrying Double-Stranded DNA for Affinity Separation of Genotoxins

We immobilized double-stranded DNA on poly(N-isopropylacrylamide), which is temperature-sensitive and gives precipitates from an aqueous solution when heated over 31°C. Photochemical conjugation with a vinyl derivative of psoralen was demonstrated to make the DNA polymerizable with a vinyl monomer. The radical copolymerization with N-isopropylacrylamide gave the temperature-responsive conjugate. The conjugate was shown to capture ethidium, a DNA-binding genotoxin, and precipitate with it when heated. About 95% of ethidium was separated from its highly diluted solution (3 ppm).