A freeze fracture technique for examining human hair medulla with Scanning and Transmission Electron Microscopy

Liquid Nitrogen ◽

Human Hair ◽

Freeze Fracture ◽

Low Viscosity ◽

Transmission Electron ◽

Examination of hair medulla by transmission electron microscopy (TEM) is difficult because of the keratinous composition of hair and because of sectioning problems that result from insufficient infiltration and nonmiscibility of hair with embedding resins, even those of low viscosity. Although longitudinally cutting or tearing fibers will expose the medulla for embedment or direct viewing, considerable disruption occurs in its structure. Less disruption results from the use of freeze fracture techniques for either transmission or scanning electron microscopy (SEM).Freshly plucked human scalp and beard hairs were submersed in liquid nitrogen for a minimum of three minutes, held at proximal and distal ends with Dumont #10 tweezers, and slowly bent to an arc until the specimens broke at the apex. Customarily, clean bevelled fractures occurred along the tips of the arcs and exposed not only the medulla but also the cortex and cuticle. The fractured specimens were then removed from liquid nitrogen.

Distribution of Cilia in the Rat Nephron Studied by Scanning Electron Microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100051402 ◽

1974 ◽

Vol 32 ◽

pp. 278-279

Author(s):

V. R. Mumaw ◽

B. L. Munger

Keyword(s):

Electron Microscopy ◽

Electron Microscope ◽

Scanning Electron Microscope ◽

Surface Topography ◽

Freeze Fracture ◽

Renal Epithelium ◽

Transmission Electron ◽

The use of the scanning electron microscope (SEM) has become a very useful tool complimenting studies done by transmission electron microscopy (TEM). The presence of cilia in the renal epithelium have been noted by various investigators and described by Latta. The present study utilizing the SEM and a freeze fracture technique demonstrates the regularity of cilia as well as the surface topography of the renal epithelium in a fractured profile.

Cuticular Ridges in a Mite

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100072228 ◽

1973 ◽

Vol 31 ◽

pp. 356-357

Author(s):

John H. Crowe

Keyword(s):

Electron Microscopy ◽

Epoxy Resin ◽

Structural Properties ◽

Panonychus Citri ◽

Low Viscosity ◽

Transmission Electron ◽

Silver Paint ◽

Many species of arachnids possess cuticular ridges, the function of which is not known. In the present investigation the structural properties of the ridges in a Trombidiform mite, Panonychus citri were studied, with a view towards discovering the function of the ridges.For scanning electron microscopy the animals were mounted on metal pos s previously coated with conducting silver paint. Best results were obtained by examining live animals, mounted on the posts immediately before examination. For transmission electron microscopy the animals were fixed in cacodylate-buffered glutaraldehyde, post-fixed in osmium, embedded in Spurr's low viscosity epoxy resin, and sectioned on diamond knives.

Cuticular Pores in a Marine Mite

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100094073 ◽

1972 ◽

Vol 30 ◽

pp. 164-165

Author(s):

John H. Crowe

Keyword(s):

Electron Microscopy ◽

Fine Structure ◽

Epoxy Resin ◽

Low Viscosity ◽

Transmission Electron ◽

Freeze Dried ◽

Several species of marine mites are known to possess elaborate cuticular pores, the function of which is not known (Newell, 1947). In the present investigation the fine structure of the cuticular pores in a Halacarid mite, Copidognathus curtusi was studied, with a view towards discovering the function of the pores.For scanning electron microscopy the animals were fixed in cacodylatebuffered glutaraldehyde, post-fixed in osmium, and freeze-dried. For transmission electron microscopy they were fixed as above, embedded in Spurr's low viscosity epoxy resin, and sectioned on diamond knives.C. curtusi was chosen for study because of the abundance of pores in its cuticle.

Ultrastructure of the dormant and germinating sporangiospore of Phascolomyces articulosus (Mucorales)

Canadian Journal of Botany ◽

10.1139/b78-085 ◽

1978 ◽

Vol 56 (7) ◽

pp. 747-753 ◽

Cited By ~ 5

Author(s):

P. Jeffries ◽

T. W. K. Young

Keyword(s):

Electron Microscopy ◽

Freeze Fracture ◽

Spore Wall ◽

Wall Layer ◽

Thin Sections ◽

Transmission Electron ◽

Sporangial Wall ◽

Using results obtained with light and scanning electron microscopy of critical-point-dried material and transmission electron microscopy of carbon replicas and freeze-fracture and ultra-thin sections, the structure and germination of the sporangiospore of Phascolomyces articulosus Boedijn is described. The sporangial wall is trilaminate and the ornamented spore wall is two layered. During germination, a new wall layer develops between the plasmalemma and the original spore wall. Sporangial structure is related to that of other members of the Thamnidiaceae and the use of germinating spores of P. articulosus for infection studies of the mycoparasite Piptocephalis unispora is indicated.

Two- or three-way observations of the identical cell elements within the same sections by LM, TEM and/or SEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100081279 ◽

1978 ◽

Vol 36 (2) ◽

pp. 82-83 ◽

Cited By ~ 1

Author(s):

Nakazo Watari ◽

Yasuaki Hotta ◽

Yoshio Mabuchi

Keyword(s):

Electron Microscopy ◽

Fine Structure ◽

Light Microscopy ◽

Thin Sections ◽

Transmission Electron ◽

Identical Cell ◽

Electron Microscopes ◽

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).

Comparative Study of the Fine Morphology of Sensory Receptors in Aspidogaster conchicola and Cotylaspis insignis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100094000 ◽

1972 ◽

Vol 30 ◽

pp. 150-151

Author(s):

Venita F. Allison ◽

J. E. Ubelaker ◽

J. H. Martin

Keyword(s):

Electron Microscopy ◽

Nervous System ◽

Osmic Acid ◽

Sensory Receptors ◽

Transmission Electron ◽

Sensory Structures ◽

Fine Morphology ◽

It has been suggested that parasitism results in a reduction of sensory structures which concomitantly reflects a reduction in the complexity of the nervous system. The present study tests this hypothesis by examining the fine morphology and the distribution of sensory receptors for two species of aspidogastrid trematodes by transmission and scanning electron microscopy. The species chosen are an ectoparasite, Cotylaspis insignis and an endoparasite, Aspidogaster conchicola.Aspidogaster conchicola and Cotylaspis insignis were obtained from natural infections of clams, Anodonta corpulenta and Proptera purpurata. The specimens were fixed for transmission electron microscopy in phosphate buffered paraformaldehyde followed by osmic acid in the same buffer, dehydrated in an ascending series of ethanol solutions and embedded in Epon 812.

Anisotropic Membranes as Substrates for Sem

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100092189 ◽

1976 ◽

Vol 34 ◽

pp. 444-445

Author(s):

Thomas P. Turnbull ◽

W. F. Bowers

Keyword(s):

Electron Microscopy ◽

High Flow ◽

Polymer Chemistry ◽

Surface Porosity ◽

Transmission Electron ◽

Pore Texture ◽

Spongy Layer ◽

Until recently the prime purposes of filters have been to produce clear filtrates or to collect particles from solution and then remove the filter medium and examine the particles by transmission electron microscopy. These filters have not had the best characteristics for scanning electron microscopy due to the size of the pores or the surface topography. Advances in polymer chemistry and membrane technology resulted in membranes whose characteristics make them versatile substrates for many scanning electron microscope applications. These polysulphone type membranes are anisotropic, consisting of a very thin (0.1 to 1.5 μm) dense skin of extremely fine, controlled pore texture upon a much thicker (50 to 250μm), spongy layer of the same polymer. Apparent pore diameters can be controlled in the range of 10 to 40 A. The high flow ultrafilters which we are describing have a surface porosity in the range of 15 to 25 angstrom units (0.0015-0.0025μm).

Digital imaging: When should one take the plunge?

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100165471 ◽

1996 ◽

Vol 54 ◽

pp. 602-603

Author(s):

John F. Mansfield

Keyword(s):

Electron Microscopy ◽

Optical Microscopy ◽

Digital Imaging ◽

Storage Devices ◽

Major Benefit ◽

Transmission Electron ◽

New Instrument ◽

The current imaging trend in optical microscopy, scanning electron microscopy (SEM) or transmission electron microscopy (TEM) is to record all data digitally. Most manufacturers currently market digital acquisition systems with their microscope packages. The advantages of digital acquisition include: almost instant viewing of the data as a high-quaity positive image (a major benefit when compared to TEM images recorded onto film, where one must wait until after the microscope session to develop the images); the ability to readily quantify features in the images and measure intensities; and extremely compact storage (removable 5.25” storage devices which now can hold up to several gigabytes of data).The problem for many researchers, however, is that they have perfectly serviceable microscopes that they routinely use that have no digital imaging capabilities with little hope of purchasing a new instrument.