“Naturally occurring branched-chain polyamines induce a crosslinked meshwork structure in a giant DNA”, Akira Muramatsu, Yuta Shimizu, Yuko Yoshikawa, Wakao Fukuda, Naoki Umezawa, Yuhei Horai, Tsunehiko Higuchi, Shinsuke Fujiwara, Tadayuki Imanaka, and Kenichi Yoshikawa, J. Chem. Phys., in press.