抄録
Using the pulse injection method, single-stranded DNA and double-stranded plasmid DNA have been deposited on well-defined Cu (111) surfaces under ultra-high vacuum (UHV) condition to obtain high resolution scanning tunneling microscopy (STM) images. These particular UHV-STM images have revealed that DNA molecules are adsorbed directly onto a clean Cu (111) surface, and exhibited the detailed structures of DNA which have not been resolved earlier. The single-stranded DNA oligomers have exhibited the images of individual internal base molecules and helix structures made of complementary base sequence. For the double-stranded plasmid DNA, the images has visualized Watson-Crick double-helix structures.
