AFFINITY GEL-ELECTROPHORESIS OF NUCLEIC-ACIDS - SPECIFIC BASE-SELECTIVE AND SHAPE-SELECTIVE SEPARATION OF DNA AND RNA ON POLYACRYLAMIDE-NUCLEOBASE CONJUGATED GEL

Two types of affinity gels consisting of cross-linked polyacrylamide a nd affinity ligands possessing nucleic acid bases were prepared. One t ype of gel was polyacrylamide-poly(vinylnucleobase) conjugated gel, wh ere the poly(vinylnucleobase) such as poly(9-vinyladenine) (PVAd) bear ing a nucleobase in the side-chain was entrapped in the gel matrix. Th e other type of gel, in which a nucleobase such as adenine is chemical ly bonded to polyacrylamide gel, was prepared by copolymerization of a crylamide, cross-linker and 9-Vinyladenine. These affinity gels, espec ially the former, demonstrated characteristic nucleobase- and shape se lective separation of nucleic acids. The gels showed high affinity for single-stranded DNA and both single- and double-stranded polynucleoti des and could separate a double-stranded DNA in mixtures of double-str anded DNA and polynucleotides. The electrophoretic mobilities of poly( uridylic acid) and poly(inosinic acid) were selectively retarded even in the presence of 7 M urea. The electrophoretic behaviours of nucleic acids on the polyacrylamide-PVAd conjugated gels were compared with t hose on the agarose-PVAd conjugated gel. The effects of urea, temperat ure and concentration of PVAd were also examined. The polyacrylamide-P VAd conjugated gel served to elucidate interactions between PVAd and n ucleic acids that could not be detected by usual spectroscopic methods .