Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Low-energy electron holographic imaging of individual tobacco mosaic
  virions   Modern structural biology relies on NMR, X-ray crystallography and
cryo-electron microscopy for gaining information on biomolecules at nanometer,
sub-nanometer or atomic resolution. All these methods, however, require
averaging over a vast ensemble of entities and hence knowledge on the
conformational landscape of an individual particle is lost. Unfortunately,
there are now strong indications that even X-ray free electron lasers will not
be able to image individual molecules but will require nanocrystal samples.
Here, we show that non-destructive structural biology of single particles has
now become possible by means of low-energy electron holography. As an example,
individual tobacco mosaic virions deposited on ultraclean freestanding graphene
are imaged at one nanometer resolution revealing structural details arising
from the helical arrangement of the outer protein shell of the virus. Since
low-energy electron holography is a lens-less technique and since electrons
with a deBroglie wavelength of approximately 1 Angstrom do not impose radiation
damage to biomolecules, the method has the potential for Angstrom resolution
imaging of single biomolecules.

30
The categories of this paper are: q-alg
27
The categories of this paper are: comp-gas
36
The categories of this paper are: cmp-lg
6
The categories of this paper are: astro-ph
25
The categories of this paper are: patt-sol
12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
33
The categories of this paper are: plasm-ph
15
The categories of this paper are: nucl-ex
17
The categories of this paper are: q-fin
7
The categories of this paper are: hep-th
8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat
21
The categories of this paper are: adap-org
31
The categories of this paper are: ao-sci
34
The categories of this paper are: chem-ph