>BY BERNARD DIXON
European Editorial Office
" By depositing calf thymus DNA onto graphite, to serve as the conductive surface for electron tunneling, a Lawrence Livermore/Lawrence Berkeley Laboratory team has produced some astonishing pictures of the topography of this key macromolecule. Major and minor grooves can be distinguished, and some of the double-stranded DNA molecules appear as twisted ladders
T.P. Beebe, T.E. Wilson, D.F. Ogletree, et al, “Direct observation of native DNA structures with the scanning tunneling microscope,” Science, 243, 370-2,20 January 1989.
Although the conventional electron microscope has been a uniquely powerful research tool over. the past two decades, its images have suggested that microtubules are the sole components of the skeleton of plant cells. As surveyed in the first of a new series of review journals, however, light microscopy and novel labeling techniques are now highlighting actin filaments as equally...