NOVEL ACRYLAMIDO MONOMERS WITH HIGHER HYDROPHILICITY AND IMPROVED HYDROLYTIC STABILITY .3. DNA SEPARATIONS BY CAPILLARY ELECTROPHORESIS IN POLY(N-ACRYLOYLAMINOPROPANOL)

Separation of DNA fragments in a novel polymer network, consisting of N-acryloylaminopropanol (AAP) is reported. The performance of this nov el monomer, as a sieving liquid polymer in capillary zone electrophore sis, was evaluated. In 50 mu m ID capillaries, an 8% solution of poly( AAP) can afford apex-resolution of the 123/124 bp adjacent pair of DNA fragments in marker V, typically unresolved in any poly(acrylamide) f ormulation. It is proposed that the distal -OH group in the AAP molecu le can form transient H-bonds with the DNA double helix. Molecular mod eling shows a meandering structure for poly(AAP), lacing the walls of half a cylinder, with kinks protruding at regular intervals, potential ly able to fit into the major groove of DNA. Contrary to previously he ld beliefs, there seems to be a minimum length of the polymer for prop er sieving of DNAs. For poly(acrylamides), a weight average molecular mass M(w) 30 000 polymer offers no resolution, whereas a polymer of 25 0 000 to 400 000 Da exhibits optimum resolving power. For poly(AAP), t he optimal length is in excess of 450 000 Da in M(w). Thus, it is show n that both the chemical composition of the monomer and the length of the polymer play a subtle, cooperative role in DNA separation.