ISSN:
0741-0581
Keywords:
TEM
;
Parallax equation
;
Freeze-etch
;
Pt-C replication
;
Hydrated spermidine-condensed DNA toruses
;
Stereoheight measurements
;
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Natural Sciences in General
Notes:
Stereoimaging of hydrated single complex macromolecules requires thin freeze-etch platinum-carbon replicas (≤200 Å) and that the transmission electron microscope (TEM) be equipped with a tilt-rotation eucentric goniometer stage. The original parallax equation is an accurate approximation for high-magnification work, micrographs (105 ×) being less than 0.3% in error. In addition, we have derived formulas for high-magnification work to measure heights, lateral distances, and the object tilt angle for an object not lying flat on the film surface. The accuracy of the height measurements is evaluated on spermidine-condensed DNA toruses. By using the maximum error equation derived from the original parallax equation, we discuss methods to improve the height measurement precision (95% fractile) to the 5-10 Å range.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jemt.1060010406
Permalink
