Circular plasmid DNA (pEGFP, 3.4 kb) with local single-stranded loops deposited on HOPG substrate by using graphite modifier (GM).
The image was obtained with Ntegra SPM in semicontact mode in air. Super-sharp NSG01_DLC probe was used.
The sample was kindly given by I. I. Agapov and E.A. Tonevitsky, Institute for transplantation and artificial organs, Moscow, Russia.