DNA01 is Plasmid pGem7zf+ (Promega) which is linearized with the SmaI endonuclease. A linear DNA molecules (3000 b. p.) are deposited onto freshly cleaved mica. Molecules are uniformly distributed on the surface with molecule density — 0,5-7 molec./um2 and typical DNA length 1009nm. Recommended humidity for obtaining a good image is 3-5%.