High Resolution DNA

Consecutive up and down scans of a single DNA molecule in buffer taken with a 30 µm lever at an amplitude of about 8 Å. The nominal helix pitch is 3.4 nm, with a major groove width of 2.2 nm and a minor groove width of 1.2 nm. You can see 6 grooves along the 10 nm scale bar, so both the major and minor groove are clearly resolved.