Scanning Electron Microscopy of Dried and Acid Treated Shells of Difflugia

1973 ◽  
Vol 31 ◽  
pp. 448-449
Author(s):  
Barry S. Eckert ◽  
S. M. McGee-Russell
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Critical Point ◽  
Point Method ◽  
External Structure ◽  
Cell Locomotion ◽  
Single Opening ◽  
Scanning Electron

Difflugia lobostoma is a shelled amoeba. The shell is an external structure of considerable mass which presents the animal with special restrictions in cell locomotion which are met by the development of active pseudopodial lobopodia containing, apparently, an organized system of thick and thin microfilaments (Eckert and McGee-Russell, 1972). The shell is constructed of sand grains picked up from the environment, and cemented into place with a secretion. There is a single opening through which lobopods extend. The organization of the shell was studied by scanning electron microscopy (SEM).Intact shells or animals with shells were dried by the critical point method of Anderson (1966) or air dried, after primary fixation in glutaraldehyde.

Preservation of Plant Cell Surfaces For Scanning Electron Microscopy

1973 ◽  
Vol 31 ◽  
pp. 472-473
Author(s):  
Linda M. Sicko ◽  
Thomas E. Jensen
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Critical Point ◽  
Filter Paper ◽  
Freeze Drying ◽  
Cell Surfaces ◽  
Air Drying ◽  
Popular Method ◽  
Critical Point Drying ◽  
Scanning Electron

The use of critical point drying is rapidly becoming a popular method of preparing biological samples for scanning electron microscopy. The procedure is rapid, and produces consistent results with a variety of samples. The preservation of surface details is much greater than that of air drying, and the procedure is less complicated than that of freeze drying. This paper will present results comparing conventional air-drying of plant specimens to critical point drying, both of fixed and unfixed material. The preservation of delicate structures which are easily damaged in processing and the use of filter paper as a vehicle for drying will be discussed.

Delicate Botanical Specimens Preserved for Scanning Electron Microscopy by Critical Point Drying

1971 ◽  
Vol 29 ◽  
pp. 450-451
Author(s):  
Arthur L. Cohen ◽  
Gerald E. Garner
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Critical Point ◽  
Freeze Drying ◽  
Animal Cell ◽  
Pollen Grains ◽  
Scanning Electron Micrographs ◽  
Animal Cells ◽  
Critical Point Drying ◽  
Scanning Electron

The surface forms and structures of animal cells have been strikingly preserved for scanning electron microscopy by freeze-drying and by critical point drying both by the method with CO2 used as the transitional fluid and the later procedure which uses a fluorocarbon (Freon 13) as a medium for the transition from the liquid to the gaseous environment. Freeze-drying is often prolonged (5-12 hours as compared with an hour or less by the critical point method) and in our experience with mold cultures on agar, the substrate shrivels and cracks and hyphal filaments are distorted.Despite, and possibly because of a flexible but inelastic cell wall, plant cells often show greater distortion than do animal cells after evaporative drying or replacement dehydration for mixrotechnical work. The animal cell membrane can contract more or less uniformly on drying - as shown by the numerous micrographs of well-preserved erythrocytes, while plant cell walls often crumple. The many scanning electron micrographs of partially collapsed pollen grains bear witness to this fact.

Intra- and inter-familial homologies of maxillary palpal sensilla of larval Simuliidae (Diptera: Culicomorpha)

1980 ◽  
Vol 58 (12) ◽  
pp. 2264-2279 ◽  
Author(s):  
D. A. Craig ◽  
A. Borkent
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Linear Array ◽  
External Structure ◽  
First Instar ◽  
Scanning Electron

Light and scanning electron microscopy was used to examine innervation and external structure of maxillary sensilla of larvae of various species of Prosimulium, Twinnia, Gymnopais, Crozetia, Stegopterna, Cnephia, Metacnephia, Gigantodax and Simulium, with emphasis on palpal sensilla. For the palpus, 12 apical sensilla of six distinct morphological types are described, named, and homologies established within the Simuliidae. First instar larvae of Prosimulium, Twinnia, and Gymnopais have a linear array of apical sensilla plus apical spicules, both characters synapomorphic for these three taxa. Prosimuliini genera possess cuticular plates around the palpus apex, synapomorphic for these taxa.Interfamilial homologies for most of the Simuliidae larval palpal sensilla are established for those of larvae of Thaumaleidae, Chironomidae, Tanyderidae, and Blephariceridae. Very few homologies could be established for the Culicidae. Thirteen or 14 palpal sensilla appear to be plesiomorphic for larval nematocerous Diptera, with Simuliidae and Culicidae having reduced numbers.

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