Figure 1.
(a) Force-distance profiles between the DNA layer and mica when the DNA is initially incubated on mica in a buffer solution containing 10 mM of MgCl2 (
and 
), CoCl2 (
and 
) or NaCl (
and 
). Open symbols(
, 
and 
): the force curves when two surfaces are brought together (in-run); solid symbols (
, 
and 
): the force curves when two surface are separated (out-run). The semi-log plots of the in-run profiles in both MgCl2 and CoCl2 are shown in the inset. (b) Schematics of the DNA conformation adsorbed on the mica substrate in the SFA incubated in MgCl2 or CoCl2.