Single DNA molecules can be rendered visible in the electron microscope by "staining" with water-soluble salts of heavy metals. The best results were obtained with lanthanum nitrate, uranyl acetate, and lead perchlorate. The molecules appear as filaments approximately 20 A wide. Their length was not determined, but it could be shown that it varied with the molecular weight of the DNA used. The same heavy metal salts will preferentially "stain" the nucleic acid in a protein-DNA complex. Evidence is provided for the possibility of a partial separation of a double-stranded molecule into single strands on adsorption to the supporting film.
Article| November 01 1961
ELECTRON MICROSCOPY OF DNA MOLECULES "STAINED" WITH HEAVY METAL SALTS
From The Rockefeller Institute
Received: July 07 1961
Copyright, 1961, by The Rockefeller Institute Press
Walther Stoeckenius; ELECTRON MICROSCOPY OF DNA MOLECULES "STAINED" WITH HEAVY METAL SALTS . J Biophys and Biochem Cytol 1 November 1961; 11 (2): 297–310. doi: https://doi.org/10.1083/jcb.11.2.297
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