The stabilization of latex in laticifers of the Convolvulaceae: application of freezing methods for scanning electron microscopy

1988 ◽  
Vol 66 (6) ◽  
pp. 1217-1226 ◽  
Author(s):  
B. A. Fineran ◽  
J. M. Condon
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Turgor Pressure ◽  
Specimen Preparation ◽  
Central Vacuole ◽  
Middle Portion ◽  
Freeze Dried ◽  
Freeze Fixation ◽  
Scanning Electron ◽  
Peripheral Cytoplasm

The high turgor pressure of many laticifers in the Convolvulaceae causes the cell contents to be disturbed when tissues are excised from the plant before specimen preparation for microscopy. This has been overcome by freezing the tissue intact on the plant, or where this is not practicable, excising a length of the organ and freezing the middle portion. Specimens are frozen and fractured in nitrogen slush, then freeze-dried and examined by scanning electron microscopy. With this method, latex particles were well preserved within the central vacuole and the peripheral cytoplasm was retained in several taxa. The need to freeze bulky pieces of tissue, however, results in poor freeze-fixation of the cytoplasm.

X-ray microanalysis of frozen-hydrated, freeze-dried, and critical point dried leaf specimens: determination of soluble and insoluble chemical elements at Erysiphe graminis epidermal cell papilla sites in barley isolines containing Ml-o and ml-o alleles

1993 ◽  
Vol 71 (2) ◽  
pp. 284-296 ◽  
Author(s):  
R. J. Zeyen ◽  
G. G. Ahlstrand ◽  
T. L. W. Carver
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Critical Point ◽  
Epidermal Cell ◽  
Erysiphe Graminis ◽  
Specimen Preparation ◽  
X Ray ◽  
Freeze Dried ◽  
Leaf Epidermal Cell ◽  
Scanning Electron

Three specimen preparation procedures were used in conjunction with scanning electron microscopy and energy dispersive X-ray microanalysis to determine, by comparison among preparation methods, both soluble and insoluble elements at Erysiphe graminis – barley leaf epidermal cell encounter site areas where attempted fungal penetration by appressoria failed. Near isogenic lines (RISO 5678-R and RISO 5678-S) of barley differing by mutation at the Ml-o locus were used. The recessive ml-o allele conditions barley epidermal cells to respond with papilla-associated resistance to E. graminis, while the dominant Ml-o allele allows for successful penetration of the majority of E. graminis germlings. Frozen-hydrated and freeze-dried specimens maintained soluble and insoluble elements, while specimens fixed by formalin – acetic acid – alcohol and critical point dried lost soluble elements. The effects of specimen preparation on electron-beam penetration and depth of X-ray excitation were calculated and are illustrated. Mean elemental intensity values were corrected for X-ray absorption by nickel coating of specimens (used for electrical conductivity) and for X-ray detector efficiency. The elements Cl, K, Mn, Ca, and Mg were highly soluble both at recently deposited (16 h) and at matured (24 h) papilla deposition sites. Elemental Si levels were elevated and in a partially soluble state in recently deposited papilla sites (16 h), but Si became bound or insoluble in matured (24 h) papilla sites. Elemental P and S are insoluble. The physiological role of each element is briefly discussed relative to its known function in healthy and diseased plants, with emphasis on E. graminis – barley epidermal cell encounter site penetration failure. Key words: Erysiphe graminis, Hordeum vulgare, X-ray microanalysis, scanning electron microscopy.

Scanning and Transmission Microscopy of Nematocyst Batteries in Epitheliomuscular Cells of Hydra

1971 ◽  
Vol 29 ◽  
pp. 410-411 ◽  
Author(s):  
Jane A. Westfall ◽  
S. Yamataka ◽  
Paul D. Enos
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Osmium Tetroxide ◽  
External Surface ◽  
Three Dimensional ◽  
Surface Structures ◽  
Transmission Microscopy ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Scanning Electron

Scanning electron microscopy (SEM) provides three dimensional details of external surface structures and supplements ultrastructural information provided by transmission electron microscopy (TEM). Animals composed of watery jellylike tissues such as hydras and other coelenterates have not been considered suitable for SEM studies because of the difficulty in preserving such organisms in a normal state. This study demonstrates 1) the successful use of SEM on such tissue, and 2) the unique arrangement of batteries of nematocysts within large epitheliomuscular cells on tentacles of Hydra littoralis.Whole specimens of Hydra were prepared for SEM (Figs. 1 and 2) by the fix, freeze-dry, coat technique of Small and Màrszalek. The specimens were fixed in osmium tetroxide and mercuric chloride, freeze-dried in vacuo on a prechilled 1 Kg brass block, and coated with gold-palladium. Tissues for TEM (Figs. 3 and 4) were fixed in glutaraldehyde followed by osmium tetroxide. Scanning micrographs were taken on a Cambridge Stereoscan Mark II A microscope at 10 KV and transmission micrographs were taken on an RCA EMU 3G microscope (Fig. 3) or on a Hitachi HU 11B microscope (Fig. 4).

Scanning Electron Microscopy-cuticular Lesions on the Roundworm Ascaris Suum

1970 ◽  
Vol 28 ◽  
pp. 114-115
Author(s):  
P. A. Madden ◽  
W. R. Anderson
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Freeze Drying ◽  
Room Temperature ◽  
Secondary Electron ◽  
Distilled Water ◽  
Freeze Dried ◽  
Silver Paint ◽  
To Come ◽  
Scanning Electron

The intestinal roundworm of swine is pinkish in color and about the diameter of a lead pencil. Adult worms, taken from parasitized swine, frequently were observed with macroscopic lesions on their cuticule. Those possessing such lesions were rinsed in distilled water, and cylindrical segments of the affected areas were removed. Some of the segments were fixed in buffered formalin before freeze-drying; others were freeze-dried immediately. Initially, specimens were quenched in liquid freon followed by immersion in liquid nitrogen. They were then placed in ampuoles in a freezer at −45C and sublimated by vacuum until dry. After the specimens appeared dry, the freezer was allowed to come to room temperature slowly while the vacuum was maintained. The dried specimens were attached to metal pegs with conductive silver paint and placed in a vacuum evaporator on a rotating tilting stage. They were then coated by evaporating an alloy of 20% palladium and 80% gold to a thickness of approximately 300 A°. The specimens were examined by secondary electron emmission in a scanning electron microscope.

Scanning electron microscopy of human iliac bone by a simple preparation method

1990 ◽  
Vol 48 (3) ◽  
pp. 226-227
Author(s):  
Toshihiko Takita ◽  
Tomonori Naguro ◽  
Toshio Kameie ◽  
Akihiro Iino ◽  
Kichizo Yamamoto
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Preparation Method ◽  
Specimen Preparation ◽  
Real Surface ◽  
Public Attention ◽  
Preparation Methods ◽  
The Real ◽  
Simple Preparation ◽  
Scanning Electron

Recently with the increase in advanced age population, the osteoporosis becomes the object of public attention in the field of orthopedics. The surface topography of the bone by scanning electron microscopy (SEM) is one of the most useful means to study the bone metabolism, that is considered to make clear the mechanism of the osteoporosis. Until today many specimen preparation methods for SEM have been reported. They are roughly classified into two; the anorganic preparation and the simple preparation. The former is suitable for observing mineralization, but has the demerit that the real surface of the bone can not be observed and, moreover, the samples prepared by this method are extremely fragile especially in the case of osteoporosis. On the other hand, the latter has the merit that the real information of the bone surface can be obtained, though it is difficult to recognize the functional situation of the bone.

The time course of calcium deposition in shells of the barnacle (Balanus amphititre amphititre) during cyprid-juvenile metamorphosis

1994 ◽  
Vol 52 ◽  
pp. 178-179
Author(s):  
Nancy R. Wallace ◽  
Craig C. Freudenrich ◽  
Karl Wilbur ◽  
Peter Ingram ◽  
Ann LeFurgey
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Time Course ◽  
Vertical Plane ◽  
Mantle Cavity ◽  
Qualitative Assessment ◽  
Calcium Deposition ◽  
Free Swimming ◽  
Freeze Dried ◽  
Scanning Electron

The morphology of balanomorph barnacles during metamorphosis from the cyprid larval stage to the juvenile has been examined by light microscopy and scanning electron microscopy (SEM). The free-swimming cyprid attaches to a substrate, rotates 90° in the vertical plane, molts, and assumes the adult shape. The resulting metamorph is clad in soft cuticle and has an adult-like appearance with a mantle cavity, thorax with cirri, and incipient shell plates. At some time during the development from cyprid to juvenile, the barnacle begins to mineralize its shell, but it is not known whether calcification occurs before, during, or after ecdysis. To examine this issue, electron probe x-ray microanalysis (EPXMA) was used to detect calcium in cyprids and juveniles at various times during metamorphosis.Laboratory-raised, free-swimming cyprid larvae were allowed to settle on plastic coverslips in culture dishes of seawater. The cyprids were observed with a dissecting microscope, cryopreserved in liquid nitrogen-cooled liquid propane at various times (0-24 h) during metamorphosis, freeze dried, rotary carbon-coated, and examined with scanning electron microscopy (SEM). EPXMA dot maps were obtained in parallel for qualitative assessment of calcium and other elements in the carapace, wall, and opercular plates.

Scanning electron microscopy of plant cells using a variable-pressure SEM and cryogenic techniques

1993 ◽  
Vol 51 ◽  
pp. 260-261
Author(s):  
M. Yamada ◽  
K. Ueda ◽  
K. Kuboki ◽  
H. Matsushima ◽  
S. Joens
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Saturated Vapor ◽  
Plant Cells ◽  
Variable Pressure ◽  
Specimen Preparation ◽  
Operating Pressure ◽  
Vapor Pressures ◽  
Low Temperature Microscopy ◽  
Scanning Electron

Use of variable Pressure SEMs is spreading among electron microscopists The variable Pressure SEM does not necessarily require specimen Preparation such as fixation, dehydration, coating, etc which have been required for conventional scanning electron microscopy. The variable Pressure SEM allows operating Pressure of 1˜270 Pa in specimen chamber It does not allow microscopy of water-containing specimens under a saturated vapor Pressure of water. Therefore, it may cause shrink or deformation of water-containing soft specimens such as plant cells due to evaporation of water. A solution to this Problem is to lower the specimen temperature and maintain saturated vapor Pressures of water at low as shown in Fig. 1 On this technique, there is a Published report of experiment to have sufficient signal to noise ratio for scondary electron imaging at a relatively long working distance using an environmental SEM. We report here a new low temperature microscopy of soft Plant cells using a variable Pressure SEM (Hitachi S-225ON).

Intracellular structures of rapid frozen biological samples observed by high-resolution low-temperature Scanning Electron Microscopy

1989 ◽  
Vol 47 ◽  
pp. 736-737
Author(s):  
T. Inoué ◽  
H. Koike
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Low Temperature ◽  
Liquid Nitrogen ◽  
Specimen Preparation ◽  
Chemical Fixation ◽  
Brown Adipose ◽  
Critical Point Drying ◽  
Temperature Scanning ◽  
Scanning Electron

Low temperature scanning electron microscopy (LTSEM) is useful to avoid artifacts such as deformation and extraction, because specimens are not subjected to chemical fixation, dehydration and critical-point drying. Since Echlin et al developed a LTSEM, many techniques and instruments have been reported for observing frozen materials. However, intracellular structures such as mitochondria and endoplasmic reticulum have been unobservable by the method because of the low resolving power and inadequate specimen preparation methods. Recently, we developed a low temperature SEM that attained high resolutions. In this study, we introduce highly magnified images obtained by the newly developed LTSEM, especially intracellular structures which have been rapidly frozen without chemical fixation.[Specimen preparations] Mouse pancreas and brown adipose tissues (BAT) were used as materials. After the tissues were removed and cut into small pieces, the specimen was placed on a cryo-tip and rapidly frozen in liquid propane using a rapid freezing apparatus (Eiko Engineering Co. Ltd., Japan). After the tips were mounted on the specimen stage of a precooled cryo-holder, the surface of the specimen was manually fractured by a razor blade in liquid nitrogen. The cryo-holder was then inserted into the specimen chamber of the SEM (ISI DS-130), and specimens were observed at the accelerating voltages of 5-8 kV. At first the surface was slightly covered with frost, but intracellular structures were gradually revealed as the frost began to sublimate. Gold was then coated on the specimen surface while tilting the holder at 45-90°. The holder was connected to a liquid nitrogen reservoir by means of a copper braid to maintain low temperature.

scholarly journals Scanning electron microscopy of freeze-dried protein foams.

1982 ◽  
Vol 46 (11) ◽  
pp. 2881-2883 ◽  
Author(s):  
Naofumi KITABATAKE ◽  
Hirotaka SASAKI ◽  
Etsushiro DOI
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Freeze Dried ◽  
Scanning Electron

A Model Outreach Program for Teaching Scanning Electron Microscopy Technology: Successes and Failures

1998 ◽  
Vol 4 (S2) ◽  
pp. 40-41
Author(s):  
N.R. Smith ◽  
R.A. Quinta
Keyword(s):  
Electron Microscopy ◽  
Community College ◽  
Scanning Electron Microscopy ◽  
Outreach Program ◽  
Specimen Preparation ◽  
State University ◽  
Learning Module ◽  
Imaging Center ◽  
Effective Use ◽  
Scanning Electron

A partnership has developed between the Microscope and Graphic Imaging Center (MAGIC) at California State University, Hayward and Ohlone Community College. The purpose of the collaboration is to develop a program to allow community college students to gain experience in preparing and viewing samples using scanning electron microscopy technology. The learning module involves students from the Ohlone College Biology Majors Program and student mentors from CSUH. An additional component is the introduction of under-represented students into a Biology Fellowship Program in which they also participate in the SEM learning module. Participants for these programs are selected on the basis of their interest and how this experience will benefit them as expressed in a one-page written essay. Ten students are selected to participate in the programs.The objectives of the learning module are to: 1) learn specimen preparation techniques and develop skills in SEM technology; 2) gain hands-on experience and develop some laboratory skills necessary for effective use of a SEM in studying biological specimens; 3) share the experience gained with peers at their home institution.

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