A stable DNA duplex containing a non-hydrogen-bonding and non-shape-complementary base couple: interstrand stacking as the stability determining factor.

The stabilizing effect of a dG:dC base-pair can also be imparted to a DNA duplex by a non-hydrogen-bonding, non-shape-complementary nucleoside analogue when interstrand stacking interactions come into play. This is the case, for example, with dBP, which has a bipyridyl (BP) residue as a nucleobase surrogate (the picture shows a dBP:dBP pair).