Scanning Electron Microscopy
P.H. Greaves, B.P. Saville in Microscopy of Textile Fibres, 2020
The chief advantage of any type of electron microscopy lies in the greatly increased resolution which it can provide compared to that which can be achieved with light microscopy. The Scanning Electron Microscopy (SEM) should really be compared with the stereo light microscope or the reflected light microscope when its great advantage of a good depth of field will be appreciated. Certain SEMs are capable of a resolution of 3 nm but this is strongly dependent on using an ideal specimen. Depth of field is one of the big advantages which the SEM possesses when compared with the light microscope, even for images at similar magnifications. In the SEM, the energy contained in the electron beam is mostly dissipated as heat at the point of contact with the specimen. Generally speaking, very little work is required to prepare textile specimens for examination in the SEM.
Negative Stain Em
Erskine L. Palmer, Mary Lane Martin in Electron Microscopy in Viral Diagnosis, 2019
The technique of negative staining, developed by S. Brenner and R. W. Home in 1959, utilizes an electron opaque substance to surround the virus or other biological structure, giving contrast between the electron-lucent biological material and the background against which it is viewed. There are many techniques of negative stain electron microscopy, but there is no universally accepted method for grid preparation. The negative stain not only surrounds virus particle but penetrates between the viral structural units and even into the interior of the virus to delineate morphological features. Prefixation of liquid preparations of some viruses with glutaraldehyde prior to negative staining can be done to accentuate features without distorting viral stracture. The Formvar film is floated off of the agar block onto surface of a negative stain contained in a small petri dish. Three-dimensional viral stracture can sometimes be delineated by pseudoreplica technique when particles are oriented so that the view is directed toward the inside of tubular structures.
The Use of Sperm Ultra-Morphology Assessment in Assisted Reproduction
Nicolás Garrido, Rocio Rivera in A Practical Guide to Sperm Analysis, 2017
Semen examination is one of the key steps in the exploration of infertile couples. The normal ejaculate contains spermatozoa with significant changes in the size and shape of the head, the acrosome, and the intermediate part of the flagellum. Sperm morphology has been recognized as the best predictor of natural fertility or after in vitro fertilization (IVF) or intrauterine insemination. Sperm morphology is only one qualitative parameter of spermatogenesis, and the conventional sperm morphological analysis is a descriptive exploration of sperm shape from a representative sample of spermatozoa from one ejaculate. Light microscopy is the most common imaging system used in routine in reproductive biology laboratories and allows after staining of fixed sperm preparations the classification of morphologically normal or abnormal spermatozoa. The evaluation of the integrity of the different structures of the male gamete by transmission electron microscopy (TEM) or scanning electron microscopy (SEM) is important in sperm ultramorphology assessment.
Practical Application of Electron Microscopy to Neuromuscular Diseases
Published in Ultrastructural Pathology, 2013
Hans H. Goebel, Werner Stenzel
Concerning individual neuromuscular conditions, electron microscopy may be considered “essential,” “helpful,” or “wasteful.” “Essential” electron microscopy should provide a clear diagnosis, because of the disease specificity of the ultrastructural findings, in particular as to inclusions within muscle fibers, such as cylindrical spirals and reducing bodies. Electron microscopy may be “helpful” in detecting ultrastructural features preceding typical light microscopic findings, for instance, undulating tubules in endothelial cells. Congenital, metabolic, and inflammatory myopathies may often be more easily and more reliably diagnosed by means of the electron microscope. Diagnostically “wasteful” electron microscopy may pertain to muscular dystrophies, neurogenic atrophy, and myotonic diseases.
Incidence of Thin Basement Membrane Nephropathy in 990 Consecutive Renal Biopsies Examined with Electron Microscopy
Published in Ultrastructural Pathology, 2008
Ioanna Zouvani, Sophia Aristodemou, Andreas Hadjisavvas, Thalia Michael, Mary Vassiliou, Charalambos Patsias, Alkis Pierides, Kyriacos Ioannou, Kyriacos Kyriacou
Thin basement membrane nephropathy is one of the main causes of hematuria in both children and adults. It is often associated with a family history and its true incidence is unknown. Accurate diagnosis of thin basement membrane nephropathy relies on the presence of attenuated glomerular basement membranes, a finding that can be appreciated only by examination in the electron microscope. In Cyprus the department of electron microscopy has received 990 consecutive renal biopsies for diagnosis. The aim of this study is to define the incidence of thin basement membrane nephropathy in this population sample based on the results of electron microscopy.
A Case Study of Intractable Diarrhea Due to Neonatal Microvillous Inclusion Disease
Published in Fetal and Pediatric Pathology, 2017
Ozgul Bulut, Bulent Ahishali, Mine Gulluoglu, Sertac Arslanoglu
Background: Microvillous inclusion disease (MVID) is one of the most severe congenital diarrhea disorders, caused by a genetic defect in enterocyte differentiation and polarization. Case report: We describe a neonate who presented with severe weight loss, hypernatremic dehydration and metabolic acidosis due to intractable diarrhea due to MVID, confirmed by electron microscopy. Conclusion: MVID can present with severe weight loss, hypernatremic dehydration and metabolic acidosis that is life threatening. The diagnosis is made by typical findings on light microscopy and electron microscope of small bowel biopsies. The only therapeutic options at this time are total parenteral nutrition and bowel rest and intestinal transplantation.