E. Tuite et B. Norden, METHYLENE-BLUE INTERCALATES WITH TRIPLER POLY(DT)ASTERISK-POLY(DA)CENTER-DOT-POLY(DT) BUT NOT DUPLEX POLY(DA)CENTER-DOT-POLY(DT), Journal of the Chemical Society, Chemical Communications, (1), 1995, pp. 53-54
Methylene blue intercalates with tripler poly(dTdA.dT) even though it
binds to the precursor duplex poly(dA.dT) in the major groove; the sw
itch may be related to conformational modifications of the polynucleot
ide structure upon binding of the third strand.