The Effects of Drying Techniques on Clay-Rich Soil Texture

1974 ◽  
Vol 32 ◽  
pp. 466-467
Author(s):  
T. G. Naymik
Keyword(s):  
Critical Point ◽  
Liquid Nitrogen ◽  
Liquid Nitrogen Temperature ◽  
Drying Methods ◽  
Air Drying ◽  
Freeze Dried ◽  
Critical Point Drying ◽  
Set Up ◽  
The Relationship ◽  
Quartz Grains

Three techniques were incorporated for drying clay-rich specimens: air-drying, freeze-drying and critical point drying. In air-drying, the specimens were set out for several days to dry or were placed in an oven (80°F) for several hours. The freeze-dried specimens were frozen by immersion in liquid nitrogen or in isopentane at near liquid nitrogen temperature and then were immediately placed in the freeze-dry vacuum chamber. The critical point specimens were molded in agar immediately after sampling. When the agar had set up the dehydration series, water-alcohol-amyl acetate-CO2 was carried out. The objectives were to compare the fabric plasmas (clays and precipitates), fabricskeletons (quartz grains) and the relationship between them for each drying technique. The three drying methods are not only applicable to the study of treated soils, but can be incorporated into all SEM clay soil studies.

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.

Rapid Critical Point Drying of Tissues in a Parr Bomb

1972 ◽  
Vol 30 ◽  
pp. 400-401
Author(s):  
C.A. Baechler ◽  
W. C. Pitchford ◽  
J. M. Riddle ◽  
C.B. Boyd ◽  
H. Kanagawa ◽  
...  
Keyword(s):  
Critical Point ◽  
Critical Pressure ◽  
Soft Tissues ◽  
Biological Tissues ◽  
Critical Temperatures ◽  
Air Drying ◽  
The Past ◽  
Critical Point Drying ◽  
Great Stress ◽  
Infiltration Techniques

Preservation of the topographic ultrastructure of soft biological tissues for examination by scanning electron microscopy has been accomplished in the past by using lengthy epoxy infiltration techniques, or dehydration in ethanol or acetone followed by air drying. Since the former technique requires several days of preparation and the latter technique subjects the tissues to great stress during the phase change encountered during air-drying, an alternate rapid, economical, and reliable method of surface structure preservation was developed. Turnbill and Philpott had used a fluorocarbon for the critical point drying of soft tissues and indicated the advantages of working with fluids having both moderately low critical pressures as well as low critical temperatures. Freon-116 (duPont) which has a critical temperature of 19. 7 C and a critical pressure of 432 psi was used in this study.

Processing Techniques for Scanning Electron Microscopy Imaging of Giant Cells from Giant Cell Tumors of Bone

2019 ◽  
Vol 25 (6) ◽  
pp. 1376-1382
Author(s):  
Asit Ranjan Mridha ◽  
Indu Barwal ◽  
Abhishek Gupta ◽  
Abdul Majeed ◽  
Adarsh W. Barwad ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Critical Point ◽  
Giant Cell ◽  
Giant Cells ◽  
Giant Cell Tumors ◽  
Microscopy Imaging ◽  
Air Drying ◽  
Critical Point Drying ◽  
Sem Imaging ◽  
Scanning Electron

AbstractGiant cell tumor (GCT) of bone is a common benign lesion that causes significant morbidity due to the failure of modern medical and surgical treatment. Surface ultra-structures of giant cells (GCs) may help in distinguishing aggressive tumors from indolent GC lesions. This study aimed to standardize scanning electron microscopic (SEM) imaging of GC from GCT of bone. Fresh GCT collected in Dulbecco's Modified Eagle Medium was washed to remove blood, homogenized, or treated with collagenase to isolate the GCs. Mechanically homogenized and collagenase-digested GCs were imaged on SEM after commonly used drying methodologies such as air-drying, tetramethylsilane (TMS)-drying, freeze-drying, and critical point-drying (CPD) for the optimization of sample processing. The collagenase-treated samples yielded a greater number of isolated GC and showed better surface morphology in comparison to mechanical homogenization. Air-drying was associated with marked cell shrinkage, and freeze-dried samples showed severe cell damage. TMS methodology partially preserved the cell contour and surface structures, although the cell shape was distorted. GC images with optimum surface morphology including membrane folding and microvesicular structures on the surface were observed only in collagenase-treated and critical point-dried samples. Collagenase digestion and critical point/TMS-drying should be performed for optimal SEM imaging of individual GCs.

Alternative Method of Rapid Drying Vascular Specimens for Scanning Electron Microscopy

2003 ◽  
Vol 10 (2) ◽  
pp. 285-287 ◽  
Author(s):  
DáŠa Slížová ◽  
Otakar Krs ◽  
Blanka PospíŠilová
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Micrographs ◽  
Low Cost ◽  
High Rate ◽  
Drying Methods ◽  
Scanning Electron Micrographs ◽  
Air Drying ◽  
Critical Point Drying ◽  
Scanning Electron

Purpose: To report the use of hexamethyldisilazane (HMDS) as an alternative to critical point drying for preparing stented canine peripheral vessels for scanning electron microscopy (SEM). Technique: Vascular specimens were fixed in 4% formaldehyde overnight, dehydrated in a graded ethanol series, followed by immersion in 100% hexamethyldisilazane. After air drying, the specimens were mounted on stainless steel stubs, coated with gold, and examined in the SEM. The electron micrographs were of high quality, showing the layers of the vascular wall and the incorporated stent covered by a neointimal layer. The micrographs were comparable to corresponding histological sections, but detailed endothelial patterns were more visible. Conclusions: HMDS treatment and subsequent air drying provides good quality scanning electron micrographs that reveal both endothelial patterns and the layered architecture of stented vessels. The disadvantage of HMDS drying may be a shrinkage and distortion similar to other drying agents. Ease of handling, low cost, and a high rate of success are advantages that favor HMDS desiccation over other drying methods.

Biological specimen preparation for SEM by a method other than critical point drying

1987 ◽  
Vol 45 ◽  
pp. 956-957 ◽  
Author(s):  
J. L. Adams ◽  
C. J. Battjes ◽  
D. A. Buthala
Keyword(s):  
Sample Preparation ◽  
Critical Point ◽  
Biological Samples ◽  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Specimen Preparation ◽  
Biological Specimen ◽  
Air Drying ◽  
Critical Point Drying ◽  
Good Preparation

Quality sample preparation for SEM is important to observe fine details without artifacts, and good preparation requires proper fixation, dehydration, drying and coating, An alternative 5 min passage in hexamethyldisilazane (HMDS) can replace critical point crying (CPD) and gives satisfactory results on many biological samples. CPD procedure may take up to 1 h per sample to ensure adequate drying, therefore a brief rinse in HMDS followed by air drying requires less time and equipment yet provides excellent results.Various biological samples were fixed in 3% glutaraldehyde; rinsed 3 times in Millonig's phosphate buffer for 10 min each; post-fixed in 1% osmium tetroxide for 1 h; rinsed as before; fixed again in 1% tannic acid (TA) for 30 min-1 h; rinsed well and partially dehydrated to 70% ethanol; placed in 1% uranyl-acetate (UA) in the dark, overnight: rinsed with 70% ethanol until UA cleared and then dehydrated through 100% ethanol.

scholarly journals The architecture of actin filaments and the ultrastructural location of actin-binding protein in the periphery of lung macrophages.

1986 ◽  
Vol 103 (3) ◽  
pp. 1007-1020 ◽  
Author(s):  
J H Hartwig ◽  
P Shevlin
Keyword(s):  
Electron Microscopy ◽  
Critical Point ◽  
Binding Protein ◽  
The Body ◽  
Actin Binding ◽  
Actin Network ◽  
Actin Binding Protein ◽  
Freeze Dried ◽  
Critical Point Drying ◽  
Actin Fiber

A highly branched filament network is the principal structure in the periphery of detergent-extracted cytoskeletons of macrophages that have been spread on a surface and either freeze or critical point dried, and then rotary shadowed with platinum-carbon. This array of filaments completely fills lamellae extended from the cell and bifurcates to form 0.2-0.5 micron thick layers on the top and bottom of the cell body. Reaction of the macrophage cytoskeletons with anti-actin IgG and with anti-IgG bound to colloidal gold produces dense staining of these filaments, and incubation with myosin subfragment 1 uniformly decorates these filaments, identifying them as actin. 45% of the total cellular actin and approximately 70% of actin-binding protein remains in the detergent-insoluble cell residue. The soluble actin is not filamentous as determined by sedimentation analysis, the DNAase I inhibition assay, and electron microscopy, indicating that the cytoskeleton is not fragmented by detergent extraction. The spacing between the ramifications of the actin network is 94 +/- 47 nm and 118 +/- 72 nm in cytoskeletons prepared for electron microscopy by freeze drying and critical point drying, respectively. Free filament ends are rare, except for a few which project upward from the body of the network or which extend down to the substrate. Filaments of the network intersect predominantly at right angles to form either T-shaped and X-shaped overlaps having striking perpendicularity or else Y-shaped intersections composed of filaments intersecting at 120-130 degrees angles. The actin filament concentration in the lamellae is high, with an average value of 12.5 mg/ml. The concentration was much more uniform in freeze-dried preparations than in critical point-dried specimens, indicating that there is less collapse associated with the freezing technique. The orthogonal actin network of the macrophage cortical cytoplasm resembles actin gels made with actin-binding protein. Reaction of cell cytoskeletons and of an actin gel made with actin-binding protein with anti-actin-binding protein IgG and anti-IgG-coated gold beads resulted in the deposition of clusters of gold at points where filaments intersect and at the ends of filaments that may have been in contact with the membrane before its removal with detergent. In the actin gel made with actin-binding protein, 75% of actin-fiber intersections labeled, and the filament spacing between intersections is consistent with that predicted on theoretical grounds if each added actin-binding protein molecule cross-links two filaments to form an intersection in the gel.(ABSTRACT TRUNCATED AT 400 WORDS)

Artifacts on the surface of articular cartilage due to drying methods

1978 ◽  
Vol 36 (2) ◽  
pp. 680-681
Author(s):  
I. Hesse ◽  
W. Hesse
Keyword(s):  
Articular Cartilage ◽  
Critical Point ◽  
Femoral Condyle ◽  
Medial Femoral Condyle ◽  
Drying Methods ◽  
Tissue Preparation ◽  
Critical Point Drying ◽  
Cacodylate Buffer ◽  
Drying Techniques ◽  
Scanning Electron

Since the advent of scanning electron microscopy very contrasting studies on the surface topography of normal and pathological cartilage have been published. The existing literature did not respect the influence of tissue preparation, especially the effect of the drying techniques. Thus the results lead to wrong conclusions. The purpose of this paper is to compare the preservation of the surface morphology obtained from three drying techniques, i. e. air-, freeze- and critical-point drying.Our experiments were performed on normal articular cartilage of 50 sheep, on transplanted cartilage of 45 sheep and on articular cartilage taken intraoperatively from 33 patients. Three adequate samples of articular cartilage attached to bone were dissected out of the weightbearing portion of the medial femoral condyle for air-, freeze- and critical-point drying. They were rinsed in 4 changes of cacodylate buffer (pH=7. 2-7. 4).

Improving Nutritional Value of Dried Blueberries (Vaccinium corymbosum L.) Combining Microwave-Vacuum, Hot-Air Drying and Freeze Drying Technologies

2008 ◽  
Vol 4 (5) ◽  
Author(s):  
Esteban I Mejia-Meza ◽  
Jaime A. Yanez ◽  
Neal M. Davies ◽  
Barbara Rasco ◽  
Frank Younce ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Nutritional Value ◽  
Freeze Drying ◽  
Vaccinium Corymbosum ◽  
Drying Methods ◽  
Hot Air Drying ◽  
Total Polyphenols ◽  
Air Drying ◽  
Hot Air ◽  
Freeze Dried

Blueberries (Vaccinium corymbosum L.) were dried combining microwave-vacuum, hot-air drying and freeze drying technologies to retain their nutritional value. Polyphenol retention, total polyphenols, anthocyanins, and antioxidant activity were evaluated in dried blueberries. Glycoside compounds for ellagic acid, quercetin, and kaempferol exhibited a higher retention than phloridzin, and R- and S-naringin in dried blueberries following dehydration. Freeze and HA-MIVAC® dried blueberries had a higher retention of total polyphenols and anthocyanins. Freeze dried blueberries had higher antioxidant activity, followed by the combination of HA-MIVAC®, MIVAC® and HA drying methods. FD, HA-MIVAC® and MIVAC® treated blueberries had a higher retention of individual polyphenols than HA treated blueberries, indicating that the nutritional properties of berries may be retained to a greater extent when these processes are employed.

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