Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2009-2-16
pubmed:abstractText
A Monte Carlo electron-trajectory calculation has been implemented to assess the optimal detector configuration for scanning transmission electron microscopy (STEM) tomography of thick biological sections. By modeling specimens containing 2 and 3 at% osmium in a carbon matrix, it was found that for 1-microm-thick samples the bright-field (BF) and annular dark-field (ADF) signals give similar contrast and signal-to-noise ratio provided the ADF inner angle and BF outer angle are chosen optimally. Spatial resolution in STEM imaging of thick sections is compromised by multiple elastic scattering which results in a spread of scattering angles and thus a spread in lateral distances of the electrons leaving the bottom surface. However, the simulations reveal that a large fraction of these multiply scattered electrons are excluded from the BF detector, which results in higher spatial resolution in BF than in high-angle ADF images for objects situated towards the bottom of the sample. The calculations imply that STEM electron tomography of thick sections should be performed using a BF rather than an ADF detector. This advantage was verified by recording simultaneous BF and high-angle ADF STEM tomographic tilt series from a stained 600-nm-thick section of C. elegans. It was found that loss of spatial resolution occurred markedly at the bottom surface of the specimen in the ADF STEM but significantly less in the BF STEM tomographic reconstruction. Our results indicate that it might be feasible to use BF STEM tomography to determine the 3D structure of whole eukaryotic microorganisms prepared by freeze-substitution, embedding, and sectioning.
pubmed:grant
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/19110374-10087259, http://linkedlifedata.com/resource/pubmed/commentcorrection/19110374-1028211, http://linkedlifedata.com/resource/pubmed/commentcorrection/19110374-11304793, http://linkedlifedata.com/resource/pubmed/commentcorrection/19110374-12160701, http://linkedlifedata.com/resource/pubmed/commentcorrection/19110374-1236017, http://linkedlifedata.com/resource/pubmed/commentcorrection/19110374-1236025, http://linkedlifedata.com/resource/pubmed/commentcorrection/19110374-14526082, http://linkedlifedata.com/resource/pubmed/commentcorrection/19110374-14566014, http://linkedlifedata.com/resource/pubmed/commentcorrection/19110374-15522778, http://linkedlifedata.com/resource/pubmed/commentcorrection/19110374-15653077, http://linkedlifedata.com/resource/pubmed/commentcorrection/19110374-17600727, http://linkedlifedata.com/resource/pubmed/commentcorrection/19110374-17689263, http://linkedlifedata.com/resource/pubmed/commentcorrection/19110374-17710148, http://linkedlifedata.com/resource/pubmed/commentcorrection/19110374-18069000, http://linkedlifedata.com/resource/pubmed/commentcorrection/19110374-1870112, http://linkedlifedata.com/resource/pubmed/commentcorrection/19110374-2709400, http://linkedlifedata.com/resource/pubmed/commentcorrection/19110374-3521021, http://linkedlifedata.com/resource/pubmed/commentcorrection/19110374-7783184, http://linkedlifedata.com/resource/pubmed/commentcorrection/19110374-8371261, http://linkedlifedata.com/resource/pubmed/commentcorrection/19110374-8742726, http://linkedlifedata.com/resource/pubmed/commentcorrection/19110374-8760405, http://linkedlifedata.com/resource/pubmed/commentcorrection/19110374-9343574, http://linkedlifedata.com/resource/pubmed/commentcorrection/19110374-9441929, http://linkedlifedata.com/resource/pubmed/commentcorrection/19110374-9441933
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0304-3991
pubmed:author
pubmed:issnType
Print
pubmed:volume
109
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
213-21
pubmed:dateRevised
2010-9-22
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Monte Carlo electron-trajectory simulations in bright-field and dark-field STEM: implications for tomography of thick biological sections.
pubmed:affiliation
Laboratory of Bioengineering and Physical Science, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bldg. 13, Rm. 3N17, 13 South Drive, Bethesda, MD 20892-5766, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural, Research Support, N.I.H., Intramural