Recent advances in atomic force microscopy of DNA

Three advances involving DNA in atomic force microscopy (AFM) are reported here. First a HEPES‐Mg buffer has been used that improves the spreading of DNA and provides good DNA coverage with as little as 200–500 picograms per sample. Second, the new “tapping” mode has been used to improve the ease and resolution of AFM‐imaging of DNA in air. Finally, AFM images are presented of single‐stranded ΦX‐174 virion DNA with the gene 32 single‐stranded binding protein. A summary of the current state of the field and of the methods for preparing and imaging DNA in the AFM is also presented.