Visualization of RNA transcripts by atomic force microscopy

RNA transcripts following transcription with T7 RNA polymerase in vitro are visualized by atomic force microscopy. A fragment of linearized pGEMEX DNA 1414 nucleotide pairs in length containing a promoter and the transcription termination region of the bacteriophage T7 is used as template for the transcription. RNA transcripts immobilized on mica (the substrate for atomic force microscopy) form condensed, rod-like structures 122 +/- 10 nm in length with characteristic length-to-width ratio 4.5-5. Features of immobilization of RNA molecules on mica for subsequent visualization by atomic force microscopy are discussed.