Linked Life Data

2016736

Source:http://linkedlifedata.com/resource/pubmed/id/2016736

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
Pt 1
pubmed:dateCreated
1991-5-22
pubmed:abstractText
A VG Microscopes HB501 field-emission high-resolution scanning transmission electron microscope (STEM) was used to image and analyse rapidly frozen, isolated macromolecules and small organelles in tissue cryosections. Dark-field images were obtained from frozen-hydrated microtubules demonstrating that sufficient contrast is available to reveal structural information. The samples were subsequently freeze-dried in the STEM and low-dose (approximately 10(3) e/nm2) dark-field mass maps were recorded with single electron sensitivity. Elemental analysis of individual macromolecules was achievable at high dose using parallel-detection electron energy-loss spectroscopy, albeit with some structural degradation. Detection of copper (320 atoms) in di-decameric haemocyanin molecules was easily within the limits of sensitivity. Elemental analysis of hydrated cryosections is limited by radiation damage to a resolution of approximately 1 micron2. For freeze-dried sections, however, the high probe current and stable cold stage of the HB501 STEM allow energy-dispersive X-ray (EDX) microanalysis of low elemental concentrations in highly localized subcellular volumes. EDX spectra from cryosections of cerebellar cortex show that a 100-s analysis time is sufficient to quantify the calcium content of 400-nm2 regions within Purkinje cell dendrites with an uncertainty of +/- 2 mmol/kg dry weight, equivalent to +/- 12 atoms.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0022-2720
pubmed:author
pubmed:issnType
Print
pubmed:volume
161
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3-19
pubmed:dateRevised
2006-8-8
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Analysis of directly frozen macromolecules and tissues in the field-emission STEM.
pubmed:affiliation
Biomedical Engineering and Instrumentation Program, NCRR, National Institutes of Health, Bethesda, MD 20892.
pubmed:publicationType
Journal Article