Use of CTAB as a cost-effective solution to an old problem: the interference of the mucilage of desmids for scanning electron microscopy

Phycologia ◽  
2013 ◽  
Vol 52 (5) ◽  
pp. 422-425 ◽  
Author(s):  
Rosaluz Tavera ◽  
Eva Calderón
2021 ◽  
Vol 2 (2) ◽  
pp. 010-013
Author(s):  
Valantena Noory ◽  
Rahela Saeedy

The fast development of nanomaterials in the quest for green, eco-friendly routes for new products often culminates in the utilization plant biomasses for the synthesis of sustainable nanoparticles. In this study, an eco-friendly, and cost-effective method has been established for the synthesis of copper oxide nanoparticles (CuONPs) using sweet lime peel extract. The synthesized nanoparticles were characterized using UV-visible spectroscopy and scanning electron microscopy. The CuONPs formed were almost agglomerated spherical in shape with a discrete rough appearance. The particle sizes measured from scanning electron microscopy (SEM) ranged from 90-175 nm. The results revealed the cost effective, time saving, renewable, green and sustainable route for CuONPs to be formed. This may open a new avenue of methods to reuse sweet lime peels.


1996 ◽  
Vol 59 (3) ◽  
pp. 322-326 ◽  
Author(s):  
JEONG-WEON KIM ◽  
MICHAEL F. SLAVIK

Cetylpyridinium chloride (1-hexadecylpyridinium chloride, CPC) was evaluated for its effectiveness in removing or killing salmonellae attached to poultry skin. Two different treatment methods were used: (i) spraying 0.1% CPC solution at 15°C or 50°C against inoculated skin surface for 1 min at 138 kPa, and (ii) immersing inoculated skin surface in 0.1% CPC solution at room temperature for either 1 min, 1 min plus 2 min holding without CPC, or 3 min. After rinsing, cells on the skins were enumerated by conventional plating as well as direct counting from scanning electron microscopy (SEM). Compared with controls, CPC spraying reduced the numbers of salmonellae by 0.9 to 1.7 log units (87 to 98%) assayed by the plating method (P < 0.05). SEM gave results similar to plating. Generally 50°C CPC spraying showed greater reduction than 15°C CPC spraying; however, the differences were not always significant. Water spraying at either temperature did not show any reduction compared to nonsprayed skins. In the immersion test, significant differences also were noticed among the control and the three other CPC-immersed groups (P < 0.05) as assayed by plating, ranging from 1.0 to 1.6 log units, which were similar to the CPC spraying results. However, no difference was noticed among the three CPC-immersed groups. Direct counting from SEM was not a suitable method for recovering cells in CPC immersion tests because dead cells were still attached to the skin while retaining their intact morphology. On the basis of the amount of CPC used, immersion appears to be more cost-effective than spraying CPC on poultry skin.


Author(s):  
P.S. Porter ◽  
T. Aoyagi ◽  
R. Matta

Using standard techniques of scanning electron microscopy (SEM), over 1000 human hair defects have been studied. In several of the defects, the pathogenesis of the abnormality has been clarified using these techniques. It is the purpose of this paper to present several distinct morphologic abnormalities of hair and to discuss their pathogenesis as elucidated through techniques of scanning electron microscopy.


Author(s):  
P.J. Dailey

The structure of insect salivary glands has been extensively investigated during the past decade; however, none have attempted scanning electron microscopy (SEM) in ultrastructural examinations of these secretory organs. This study correlates fine structure by means of SEM cryofractography with that of thin-sectioned epoxy embedded material observed by means of transmission electron microscopy (TEM).Salivary glands of Gromphadorhina portentosa were excised and immediately submerged in cold (4°C) paraformaldehyde-glutaraldehyde fixative1 for 2 hr, washed and post-fixed in 1 per cent 0s04 in phosphosphate buffer (4°C for 2 hr). After ethanolic dehydration half of the samples were embedded in Epon 812 for TEM and half cryofractured and subsequently critical point dried for SEM. Dried specimens were mounted on aluminum stubs and coated with approximately 150 Å of gold in a cold sputtering apparatus.Figure 1 shows a cryofractured plane through a salivary acinus revealing topographical relief of secretory vesicles.


Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi

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).


Author(s):  
Ronald H. Bradley ◽  
R. S. Berk ◽  
L. D. Hazlett

The nude mouse is a hairless mutant (homozygous for the mutation nude, nu/nu), which is born lacking a thymus and possesses a severe defect in cellular immunity. Spontaneous unilateral cataractous lesions were noted (during ocular examination using a stereomicroscope at 40X) in 14 of a series of 60 animals (20%). This transmission and scanning microscopic study characterizes the morphology of this cataract and contrasts these data with normal nude mouse lens.All animals were sacrificed by an ether overdose. Eyes were enucleated and immersed in a mixed fixative (1% osmium tetroxide and 6% glutaraldehyde in Sorenson's phosphate buffer pH 7.4 at 0-4°C) for 3 hours, dehydrated in graded ethanols and embedded in Epon-Araldite for transmission microscopy. Specimens for scanning electron microscopy were fixed similarly, dehydrated in graded ethanols, then to graded changes of Freon 113 and ethanol to 100% Freon 113 and critically point dried in a Bomar critical point dryer using Freon 13 as the transition fluid.


Author(s):  
Jane A. Westfall ◽  
S. Yamataka ◽  
Paul D. Enos

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).


Author(s):  
J.N. Ramsey ◽  
D.P. Cameron ◽  
F.W. Schneider

As computer components become smaller the analytical methods used to examine them and the material handling techniques must become more sensitive, and more sophisticated. We have used microbulldozing and microchiseling in conjunction with scanning electron microscopy, replica electron microscopy, and microprobe analysis for studying actual and potential problems with developmental and pilot line devices. Foreign matter, corrosion, etc, in specific locations are mechanically loosened from their substrates and removed by “extraction replication,” and examined in the appropriate instrument. The mechanical loosening is done in a controlled manner by using a microhardness tester—we use the attachment designed for our Reichert metallograph. The working tool is a pyramid shaped diamond (a Knoop indenter) which can be pushed into the specimen with a controlled pressure and in a specific location.


Sign in / Sign up

Export Citation Format

Share Document