Scanning Microscopy of Thin Biological Specimens

1969 ◽  
Vol 27 ◽  
pp. 48-49
Author(s):  
A. V. Crewe ◽  
J. Wall
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Scanning Microscopy ◽  
Resolving Power ◽  
Electron Current ◽  
Scanning Electron ◽  
Transmission Microscope

We have recently improved our scanning electron microscope to a level that point resolution of 5 Å or so is possible. The electron current in the focused spot is about 10-10 amps so that good pictures can be obtained with a 10 sec exposure and the highest quality pictures can be obtained in 100 sec.The resolving power of this microscope is now comparable to that in a conventional transmission microscope for thin biological specimens and it is therefore of value to compare micrographs taken on the two types of instrument.

The Broad Applications of the Scanning Electron Microscope

1969 ◽  
Vol 27 ◽  
pp. 20-21
Author(s):  
C. T. Nightingale ◽  
S. E. Summers ◽  
T. P. Turnbull
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Light Microscopy ◽  
Surface Topography ◽  
Great Depth ◽  
Resolving Power ◽  
Depth Of Field ◽  
Pictorial Representations ◽  
Scanning Electron

The ease of operation of the scanning electron microscope has insured its wide application in medicine and industry. The micrographs are pictorial representations of surface topography obtained directly from the specimen. The need to replicate is eliminated. The great depth of field and the high resolving power provide far more information than light microscopy.

Resolution and measurement in the scanning electron microscope

1987 ◽  
Vol 45 ◽  
pp. 534-537 ◽  
Author(s):  
Michael T. Postek
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Engineering Design ◽  
Resolving Power ◽  
Practical Applications ◽  
Instrument Resolution ◽  
Accurate Definition ◽  
Definition Of ◽  
Scanning Electron ◽  
Better Than

The term ultimate resolution or resolving power is the very best performance that can be obtained from a scanning electron microscope (SEM) given the optimum instrumental conditions and sample. However, as it relates to SEM users, the conventional definitions of this figure are ambiguous. The numbers quoted for the resolution of an instrument are not only theoretically derived, but are also verified through the direct measurement of images on micrographs. However, the samples commonly used for this purpose are specifically optimized for the measurement of instrument resolution and are most often not typical of the sample used in practical applications.SEM RESOLUTION. Some instruments resolve better than others either due to engineering design or other reasons. There is no definitively accurate definition of how to quantify instrument resolution and its measurement in the SEM.

scholarly journals Ultrastructure of cleistothecia and the stages of life cycle of Microsphaera palczewskii by scanning electron microscope

2014 ◽  
Vol 32 (2) ◽  
pp. 275-278
Author(s):  
Joanna Z. Kadłubowska ◽  
Ewa Kalinowska-Kucharska
Keyword(s):  
Electron Microscope ◽  
Life Cycle ◽  
Scanning Electron Microscope ◽  
Scanning Microscopy ◽  
Developmental Cycle ◽  
Central Poland ◽  
Caragana Arborescens ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

Several year long investigations of the developmental cycle of <i>Microsphaera palczewskii</i> occurring on the leaves of <i>Caragana arborescens</i> in Central Poland are reported. The material was studied with light and scanning electron microscopes. The scanning microscopy micrographs of the clistothecia and appendages presented in this report are the first micrographs of this species.

Contrast Effects in High Resolution, Low Voltage SEM

1974 ◽  
Vol 32 ◽  
pp. 452-453
Author(s):  
L. M. Welter
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Scanning Electron Microscope ◽  
Field Emission ◽  
Low Voltage ◽  
Electron Source ◽  
Scanning Microscopy ◽  
Contrast Effects ◽  
Probe Current ◽  
Scanning Electron

A scanning electron microscope using a field emission electron source and a single electromagnetic lens can produce a resolution of less than 180Å using an accelerating voltage of only 900v. High resolution, low voltage (0.1-2kV) scanning microscopy offers a number of advantages over the use of higher accelerating voltages. Specimen damage may be reduced because the power (P≃IV) which must be absorbed by the specimen for operation at a given probe current (I) is decreased in proportion to the reduction in accelerating voltage (V).

Spatial Resolution of SEM Signals

1972 ◽  
Vol 30 ◽  
pp. 436-437
Author(s):  
H. Soezima
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Primary Electron ◽  
Resolving Power ◽  
X Rays ◽  
Primary Electron Beam ◽  
Scanning Electron Microscope Analysis ◽  
Electron Microscope Analysis ◽  
Scanning Electron

There are few investigations discussed on resolution of the signals as spatial resolving power, at the scanning electron microscope analysis. There remains misunderstanding that better resolution is obtained only by making a primary electron beam diameter small. At the scanning electron microscope analysis, there are such signals as secondary electron, back scattered electron, absorbed electron, transmitted electron, auger electron, cathode luminescence and X-rays. The spatial resolutions of these signals are effected not only by primary electron diameter but also by accelerating voltage, sample density, electro conductivity of the sample, surface condition of the sample, relative position among the primary electron optics, sample and detection system, energy of the signals, potential and magnetic distribution, and current density distribution of primary electron beam.Some examples of the X-rays, that have the poorest resolving power in the signals, are shown below.

Light microscope and scanning electron microscope observations of Ciboria acerina

1972 ◽  
Vol 50 (11) ◽  
pp. 2153-2156 ◽  
Author(s):  
Mary E. Elliott ◽  
Michael Corlett
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Light Microscope ◽  
Light Transmission ◽  
Tissue Structure ◽  
Tissue Type ◽  
Cell Tissue ◽  
Scanning Electron ◽  
Transmission Microscope

The tissue structure and the development of the apothecium of an inoperculate discomycete, Ciboria acerina, were studied using the light transmission microscope and the scanning electron microscope. Attention is drawn to each ascus, paraphysis, interwoven hypha, and cell tissue type more forcibly when viewed with the SEM; otherwise these methods complement each other.

scholarly journals Examination of mycological samples by means of the scanning electron microscope

1973 ◽  
Vol 7 (2) ◽  
pp. 79-85 ◽  
Author(s):  
M. Thibaut ◽  
M. Ansel
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Scanning Microscopy ◽  
Rhizopus Nigricans ◽  
Emericella Nidulans ◽  
Hull Cells ◽  
Scanning Electron

Three species of Siphomycetes: Rhizopus arhizus, Rhizopus equinus and Rhizopus nigricans, as well as a Septomycete: Emericella nidulans, have been examined by means of a scanning electron microscope. Among the difjerent Rhizopus, this technique showed differences in the appearance of the sporangia. In Emericella nidulans, scanning microscopy enábled one to ascertain that the "Hull cells" were completely hollow and also demonstrated the ornemented aspect of the ascospores.

The Alteration of the Pore Spaces in Sandstones

1973 ◽  
Vol 31 ◽  
pp. 210-211
Author(s):  
R. E. Ferrell ◽  
G. G. Paulson
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
The Other ◽  
Coarse Grained ◽  
Depositional Fabric ◽  
Soluble Components ◽  
Scanning Electron ◽  
Shape And Size

The pore spaces in sandstones are the result of the original depositional fabric and the degree of post-depositional alteration that the rock has experienced. The largest pore volumes are present in coarse-grained, well-sorted materials with high sphericity. The chief mechanisms which alter the shape and size of the pores are precipitation of cementing agents and the dissolution of soluble components. Each process may operate alone or in combination with the other, or there may be several generations of cementation and solution.The scanning electron microscope has ‘been used in this study to reveal the morphology of the pore spaces in a variety of moderate porosity, orthoquartzites.

Observability of Very Thick Specimen by Using Transmission Scanning Electron Microscope

1971 ◽  
Vol 29 ◽  
pp. 26-27
Author(s):  
K. Shibatomi ◽  
T. Yamanoto ◽  
H. Koike
Keyword(s):  
Electron Microscope ◽  
Image Quality ◽  
Scanning Electron Microscope ◽  
Chromatic Aberration ◽  
Image Contrast ◽  
Objective Lens ◽  
Thick Specimen ◽  
Transmission Electron ◽  
Scanning Electron

In the observation of a thick specimen by means of a transmission electron microscope, the intensity of electrons passing through the objective lens aperture is greatly reduced. So that the image is almost invisible. In addition to this fact, it have been reported that a chromatic aberration causes the deterioration of the image contrast rather than that of the resolution. The scanning electron microscope is, however, capable of electrically amplifying the signal of the decreasing intensity, and also free from a chromatic aberration so that the deterioration of the image contrast due to the aberration can be prevented. The electrical improvement of the image quality can be carried out by using the fascionating features of the SEM, that is, the amplification of a weak in-put signal forming the image and the descriminating action of the heigh level signal of the background. This paper reports some of the experimental results about the thickness dependence of the observability and quality of the image in the case of the transmission SEM.

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