Atomic Force Microscopy of DNA Electrophoresed onto Silylated Mica

A new technique has been developed for electrophoresing DNA molecules from an agarose gel onto a silylated mica substrate where they can be imaged with an atomic force microscope (AFM). With a simple modification, the technique can also be used for polyacrylamide gels. This method does not require purification of samples from the gels. Using tapping mode AFM, we have observed plasmids after electrophoretic separation into two bands. Differences in conformation were observed between the plasmids in the two bands