bluuebunny/crossref_metadata_2025 huggingface dataset:
Watching Rafts Move Within Cells: A Fluorescence Microscope-Based Transport Assay
Authors: Carmichael Stephen W , Salisbury Jeffery L
Published: March 2018

Imagine a raft in a canal between point A and point B. On that raft is a visible (fluorescent) cargo. Also, attached to that raft is a motor that will propel the raft only from A to B (anterograde transport). When the raft gets to point B, another motor is attached that can propel the raft, and its cargo, and the anterograde motor, back to point A (retrograde transport). Within a cell, the canals are microtubLiles, and a lot is known about anterograde and retrograde transport in some systems, but these phenomena have not been directly observed in a living, intact animal. Until now, that is. In a pair of very interesting papers, the laboratory of Jonathan Scholey has shown us convincing micrographs of anterograde and retrograde transport in an important animal model.
Surface Charging and Photoeffects on Semiconductor and Insulator Surfaces in AFM
Authors: Rossi Robert , Unger Marc
Published: March 2018

Having seen these effects often enough, and fielded questions on them from fellow AEM users, we'd like to share our speculations about surface charging effects on semiconductor and insulator surfaces. We do not claim the following to be authoritative, but just what we consider a reasonable explanation for some strange phenomena we have observed.
Dil and DiO Confocal Imaging of Chicken Embryos
Authors: Denetclaw Wilfred F
Published: March 2018

In my research, I am interested in understanding cellular morphogenetic events in early somitic myogenesis in the chicken embryo, and much of this work involves viewing fluorescently labeled cells in embryonic tissues. For this work, I am using 0.2% (weight/volume in 100% tetraglycol (Sigma)) concentrations of dil (1,1', di-octadecyl-3,3,3',3',-tetramethylindocarbocyanine perchlorate) and diO (3, 3'-dioctadecyloxacarbocyanine perchlorate) to focally label small areas (approximately 10 cells) of the epithelial somite known as the dermomyotome.
Re-Usable Vice-Style SEM Sample Holders for Pin-Mount Stages
Authors: Simkin Ben
Published: March 2018

Over a number of years, I have found it desirable to firmly hold a sample in the SEM without the contamination problems (or sample creep) associated with carbon tape. My approach to this has been to make a small vice suitable for gripping the sample which will still fit into a standard pin-mount style sample stage. I have made a number of specimen holders over the last few years, at rock-bottom prices.
Manufacturing and Processing Techniques Affecting Morphology of Pyrotechnic Oxidizer Particles
Authors: Dujay Richard C
Published: March 2018

In a pyrotechnic composition, the morphology (size, shape and surface features) of individual particles in the mixture influences both burn rate and the ease of ignition of the composition. Collectively, the larger, more rounded and smoother the particles, the lower the burn rate and the more difficult it is to ignite the composition. However, the purpose of the current investigation was only to catalogue some particle morphologies that may be useful in forensic identification of unconsumed or residual pyrotechnic evidence. In this study, potassium nitrate was chosen because of its common use in pyrotechnics and because of its similarity with other frequently used pyrotechnic oxidizers.

All samples were prepared for scanning electron microscopy using a double-sided adhesive carbon disk applied to an aluminum post. Particles were mounted to the carbon disk and sputter coated with gold.
Digital Subtraction of Lipofuscin's Fluorescence
Authors: Cornea Anda
Published: March 2018

Fluorescence imaging of brains from older animals, particularly primates, can be hindered by the presence of lipofuscin, a strongly fluorescent pigment that accumulates with age, primarily in neuronal cells. Lipofuscin has a broad emission spectrum that overlaps emission of most fluorescent labels, is present throughout the brain and other tissues, and is very hard to quench chemically (Schnella et at.. Journal of Histochemistry and Cytochemistry, Vol. 47, 719-730, 1999). A more convenient way to eliminate lipofuscin from fluorescence images is the use image arithmetic to subtract its signal. This method takes advantage of lipofuscin's broad emission spectrum that makes it appear in all fluorescence channels.
Cleaning A Microscope's Optical Surfaces
Authors: Larson Jeffrey M
Published: March 2018

Recently there was an exchange on the Confocal Listserver about the proper method for cleaning objective lenses. Some suggestions were useful and were some fraught with danger. This article is adapted from my reply to the list.

There are only three hard and fast rules about lens cleaning:

1) Never “dry” clean a lens. 2) Use a solvent or dispersant that is likely to remove whatever is on the lens. 3) Use the best quality lens tissue available.

The most likely source of damage to glass surfaces and fine optical coatings is abrasion. The particles that cause the abrasion are the particles on the objective lens surface and the particles in whatever is used to wipe the lens.
Castaing's Electron Microprobe and its Impact On Materials Science
Authors: Newbury Dale E
Published: March 2018

A central theme of modern materials science has been the exploration of the relationship between the microstructure of a material and its macroscopic properties. Beginning in the late 19th century, the developing field of metallography permitted scientists to view the microstructure of metal alloys. Mechanical polishing followed by selective chemical etching produced differential relief on chemically distinct phases or at grain boundaries. With such specimens, reflection optical microscopy revealed structures with micrometer and even finer dimensions. The microstructural world that was found proved to be highly complex, and most alloys were observed to be chemically differentiated into two or more distinct phases.
Three-Dimensional Crystallographic Analysis Beyond EBSD Mapping: The Next Dimension
Authors: Mulders JJL , Gholinia A
Published: March 2018

Since the early 1990s EBSD (Electron Back Scatter Diffraction) has been developed to become a mature crystallographic analysis technique at the micro and nano-scale. It is applied in a SEM (Scanning Electron Microscope) on samples with a very smooth and clean surface. It provides quantitative orientations of individual grains, and by mapping a larger area, multiple grain analysis, texture, and grain boundaries can be examined. As the useful information for the EBSD technique comes from a very shallow depth in the material (10 to 20nm), it is a surface analysis technique showing lateral 2D distributions of crystal orientations.
Embedding Cultured Cells Grown in Well Plates
Authors: Cohen-Gould Leona
Published: March 2018

For years, I have used a hybrid Epon-analog resin to embed in culture dishes. I use a standard Epon formula but utilize the following components: LX-112 and DMP-30 from Ladd Research Industries DDSA and NMA from Electron Microscopy Sciences I know it seems weird, but years ago I tried all sorts things, from the “straight” formulations from each vendor to a bunch of mixtures. This one has never reacted with the plastic of the dishes. Here is how I do the actual embedding of the cell monolayers in the dishes:

1) After the last 100% ethanol, remove the alcohol and cover the bottom of the well with a layer of resin mixture that is about 2 mm deep. 2) Insert embedding tubes that are made by cutting the pyramidal bottoms off of BEEM capsules (just slice them with a fresh razor blade and be sure to insert them so that the manufactured end rather than the cut one is sitting against the dish). 3) After inserting labels into the tubes, put them into the oven at 60° overnight. 4) In the morning, fill just the embedding tubes and return everything to the oven again to finish polymerizing. 5) When the resin is cured, grab the tubes with a pair of needlenosed pliers and snap them out. Sometimes a bit of the bottom of the dish comes away with the block, but often a very smooth block face results. If some of the dish comes up, it is easy to see under a dissecting microscope, and the dish portion comes away easily when trimming the block face.

I often cut away part of the block face with a jeweler's saw, either to keep it in reserve or to re-embed it in order to get cross sections, and then trim the rest into a narrow rectangle.
Scientific Ethics: What Are Our Responsibilities As Facility Managers? M&M 2001 Expert's Session on Core Facility Management
Authors: Sherman Debby
Published: March 2018

This article is the second of a series transcribed from the discussion taped during the Core Facility Management session. Bulleted paragraphs indicate comments by individuals attending the session.

D. Sherman: The next topic was suggested based on the discussion at last year's Core Facility Management session. Those of you who have not been involved in formal discussions on scientific ethics probably are going to have your eyes opened a bit. There is no such thing as a quick answer when it comes to ethics. What was initially brought up last year was the question of what are our responsibilities as facility managers when we see things going on that are perhaps not exactly appropriate as far as interpretation of data and such.
Using Fluorochromes To Label An Oil-ln-Water Emulsion
Authors: Thrift Richard
Published: March 2018

A question was asked on the microscopy listserver about fluorescent probes for studying oil-in-water emulsions trapped in a cellulose membrane, I don't have experience with that exact problem (I have studied chloroform/water emulsions rather than emulsions of triglycerides or alkanes), but I can make some general suggestions. The best type of hydrophobic probe to use depends on whether the probe is to be added to the hydrophobic phase before emulsification or after. If it is to be added to the preexisting emulsion as a dimethylsulfoxide stock solution, a probe with some aqueous solubility is required.
Food Under the Microscope
Authors: Carmichael Stephen W
Published: March 2018

We're all interested in food. Food is the sustenance of life. And you're interested in microscopy, or else you would not be reading this column. So here's a web site that will appeal to both of your interests. Miloš Kaláb is the author of the web site, and he's enlisted a host of food scientists to assist him. There's no lack of expertise here!

The home page can send you to many locations, but let's begin with the site that deals with microscopy. It is said that the earliest microscopists trained their simple instruments on food, mainly to look for contaminants. We are then treated to a primer on microscopy, beginning with light microscopy, then advancing to electron microscopy.
Microscopy in the Real World: A Manufacturer's Perspective
Authors: Kersker Michael M
Published: March 2018

What in the “real” world does this title mean? Of course, every one using an instrument will insist that his application is in some way unique and therefore not a common, mundane, “real-world” one. The “real-world” for an academically motivated scientist may be quite different from the “real-world” of the commercially motivated scientist. What happens in an asbestos testing lab is quite different from the activities of a consulting group using the microscope to solve industrial problems. Every application is “real world”…but they most certainly may be different.
Utilizing Original TEM Negatives and Micrographs For Teaching in the Digital Domain
Authors: Mascorro Josè A
Published: March 2018

Original transmission electron micrographs illustrating a variety of biological tissues are excellent tools that can be used in the education and examination of first year medical students. Many of these valued micrographs (and the negatives that produced them) date back to the 1960s, to the time when this researcher started a career in microscopy that continues to this day, To avoid returning to the darkroom and laborious photographic techniques, original negatives were scanned to produce micrographs for use in written or laboratory examinations or as images transported into Power Point lecture presentations. Original micrographs also were scanned and provided additional educational materials.
Very tiny bar codes
Authors: Carmichael Stephen W
Published: March 2018

The use of barcodes on products, combined with the computer technology to read and track the subsequent data, has revolutionized inventory control in our society. Barcodes are commonly seen on items as large as automobiles and as small as pieces of candy. But if you need to track a large number of items that are microscopic in size, such as biologically relevant molecules (think genomics, proteomics, metabolomics, etc), then you need very small barcodes. Sufficiently small rods that can be marked as barcodes have been developed by Sheila Nicewarner-Peña, Griffith Freeman, Brian Reiss, Lin He, David Peña, Ian Walton, Remy Cromer, Christine Keating, and Michael Natan.
Progress Towards More Realistic In-Situ Microscopy Observations
Authors: Howie A
Published: March 2018

As progress indicators in electron microscopy, advances in spatial resolution and in spectroscopy probably attract most frequent attention. Improved user-friendliness has also been significant even when judged in comparison with scanned probe microscopy. Evidence for developments in in-situ microscopy at least equally impressive can be found by comparing the relevant sections of the book by Hirsch et al. and a more recent compilation.

Peter Hirsch's research group swiftly discovered the power and frustrations of in-situ microscopy. The cine film of dislocation motion observed in the earliest diffraction contrast studies, and attributed to the thermal stresses generated by the electron beam, was extremely effective in convincing the wider community that it was indeed dislocations that were being observed.
Artifacts and Non-Local Effects in SPM Potential Measurements
Authors: Kalinin Sergei V , Bonnell Dawn A
Published: March 2018

In the last few years Scanning Probe Microscopy (SPM) has become one of the primary tools of science and technology. In addition to topographical imaging, surface potential, conductivity, optical, ferroelectric and magnetic properties that can be studied down to the nanometer level. However, quantitative and sometimes qualitative studies of fundamental physical phenomena in meso- and nanoscale systems are often hindered by SPM imaging artifacts. Here we briefly discuss the principles of operation and the major sources of artifacts in electrostatic measurements by SPM.

One of the most well known techniques for local potential imaging is Scanning Surface Potential Microscopy (SSPM). SSPM is based on dual pass imaging. The grounded tip acquires surface topography during the first pass.
Swapping Atoms For Bits: Managing the Digital Evolution in the Microscopy Laboratory
Authors: Murphy Judy A
Published: March 2018

Microscopy labs have very quickly moved from keeping track of and storing thousands of samples and negatives “atoms,” to having to now deal with the same number of samples, and a few negatives, but in addition, we may now have thousands of digital images “bits.” In a two-year microscopy teaching program, which includes 18 microscopy courses, there are thousands of images, which must be collected from a variety of input devices running on various platforms. These must then be associated with different types of data files that need to be tagged to reports as well as being tagged to projects and courses. All of this information must be accessible, first to all those involved with doing the project, as well as to anyone associated with needing the results.
Method for Metallization Stripping of Gold Interconnected Semiconductors Using an Aqueous Potassium Iodide Solution
Authors: Tomic Peter
Published: March 2018

Thin films in microcircuits can vary from as little a few hundred angstroms, in the case of dielectrics such as silicon nitride and silicon dioxide, to several microns in the case of interconnects. However, most metallization systems used as interconnects and in active structures are generally in the order of 0.5 μm to 4 μm. Gold has a number of desirable properties such as high electrical conductivity, the ability to be easily electroplated, low residual stress after deposition, corrosion resistance etc., Gold is commonly found in microelectronic devices, particularly in high frequency applications like cellular telephony, fiber-optic amplifiers and other high frequency analog applications. An aqueous potassium iodide solution offers a fast and relatively safe method for the removal of thin gold films.
A TEM Investigation of the Network Structure of Electron Beam Cured Epoxy Polymers
Authors: Schalek Richard L , Defoort Brigitte , Drzal Lawrence T
Published: March 2018

Glassy network epoxies have widespread applications as matrices for advanced composites As an alternative to thermal curing, electron beam (ebeam) processing has been demonstrated as a very powerful tool for achieving fast and efficient curing [1,2]. E-beam curing of epoxy based resins using suitable onium salts as initiators proceeds via a cationic mechanism. The final polymer network properties are highly dependent on processing conditions and curing kinetics. It was demonstrated that under certain processing conditions, heterogeneities can appear in the material, due to the agglomeration of initiator residue. Initially the initiator is miscible with the resin; however, reaction-induced phase separation occurs as the increasing molecular weight of the polymer reduces the solubility of the initiator.
Save That Dye!
Authors: Titford Michael
Published: March 2018

All laboratory workers face the ongoing requirement that all chemicals and solutions used in the lab be labeled with the date of receipt or preparation, together with the expiration date of the chemical and the initials of the preparer, as well as any known hazards associated with that chemical. Officials from accrediting agencies, sometimes unannounced, pick and poke around laboratories looking for outdated chemicals and solutions, including biological stains left unsuspectingly at the back of a fridge or on a seldom used shelf.
When Dinosaurs Became Extinct, What Happened to the Insects?
Authors: Carmichael Stephen W
Published: March 2018

It is widely accepted that approximately 65 million years ago, an extraterrestrial object slammed into the Yucatán Peninsula of Mexico, creating a worldwide climatic shift that wiped out the dinosaurs, and many other terrestrial and marine species. But what happened to the insects? They undoubtedly represented a larger biomass than the dinosaurs, but it's fair to say they haven't captured the public's imagination in the same way. The reason the fate of the insects has not been adequately explored is due to the paucity of the available fossil record of the insect bodies. There are a few records of insects embedded in amber or fossilized, but practically none are available from the time of mass extinction referred to as the Cretaceous-Paleocene boundary. Recently, Conrad Labandeira, Kirk Johnson, and Peter Wiif found an ingenious way to examine indirect evidence and show what happened to the insects during this time.
Designing a Microscopy/analytical Instrumentation Facility: Step by Step Procedure
Authors: Murphy Judy A
Published: March 2018

Designing a microscopy and/or analytical instrumentation facility can be completed in a step by step approach, whether it is a completely new facility or an existing one moving into expanded quarters. The procedure is independent of size. The same basic procedure is required for one room or an entire building. There are several major factors that must be taken into consideration. Check lists can be compiled by the microscopist/analyst. One should easily be able to start at any point along the way. The time and effort Initially put into the design will pay for itself many times over in both the convenience and efficiency of the resulting laboratory.
Microscopes in Art Galleries?
Authors: Carmichael Stephen W
Published: March 2018

In addition to concerns about the appearance of a display, curators of art galleries are also concerned about conservation of the artwork and their authenticity. Microscopes have played a role in these latter activities since the 1930s. Various imaging techniques, including X-radiography, infrared reflectography, macrophotography, UV-fluorescence and raking light (light source at a low angle to the surface) imaging have their advantages and disadvantages. Confocal microscopy is most useful compared to the other methods for the purpose of examination of subsurface structure, but the close working distance (a few mm) makes it precarious to use on valuable masterpieces. More recently, Haida Liang, Marta Cid, Radu Cucu, George Dobre, Adrian Podoleanu, Justin Pedro, and David Sauders have demonstrated the usefulness of optical coherence tomography (OCT) for non-destructive examination of artwork. OCT, as discussed previously in this column, is more commonly used to examine biological specimens.
Recent Advances in High-Speed Orientation Mapping
Authors: Nowell Matthew M , Chui-Sabourin Martina , Carpenter John O
Published: March 2018

Orientation mapping via automated analysis of Electron Backscatter Diffraction (EBSD) patterns has developed into an established microstructural analysis tool in the electron microscopy community. From the early 1990s, when this technique became commercially available, there has been a steady increase in the data acquisition rates as shown in Figure 1. Currently, orientation mapping speeds of over 200 analyzed patterns per second have been achieved. With these types of acquisition rates now available, the strategy on how to best use EBSD and orientation mapping has also shifted. Early adopters of this technique had to allocate hours of Scanning Electron Microscope (SEM) beam time in order to collect statistically significant data. With current technology, what was collected in hours can now be obtained in minutes. The goal of this article is to introduce this high-speed orientation mapping and present results illustrating the benefits of this capability.
Intermediate Magnification Imaging System for Whole Organs/Organisms
Authors: Cole Richard W , Mannella Carmen A , Renken Christian , Turner James N
Published: March 2018

There are many techniques for 3D imaging of biological specimens such as confocal, two-photon and, wide-field fluorescence microscopy, CAT scan, MRI, and optical coherence tomography. There are also many derivatives of these techniques, each having its strengths and weaknesses. Due to the differences in resolution, depth-of-field, and field-of-view, it is often difficult to compare images from the relatively high-resolution microscopy methods to the latter lower-resolution high-volume imaging methods. Effectively making this comparison could be very powerful in relating organ or organism level information to cellular level processes.
Tissue Digestion for Ferruginous Bodies for Light Microscopy
Authors: Gondo Margaret
Published: March 2018

Asbestos fibers are commonly called ferruginous bodies due to the iron content of the fibers. After they are inhaled, the asbestos fibers become coated with glycoprotein and hemosiderin, deposited by macrophages.

This procedure may be used on either formalin fixed, paraffin embedded blocks or formalin fixed wet tissue. Because this procedure will result in complete destruction of the tissue sample used, it is very important to obtain written approval documenting this fact from the individual requesting this procedure, if the procedure is being done for someone else. The tissue should be from the lung parenchyma. Also, it is a good idea to use sterile, disposable tubes throughout this procedure to limit the possibility of contamination.
Analysis of Printed Paper via Micro-ATR Mapping
Authors: Troost Peter , Hellgeth John W , Schiering David W , Tague Thomas J
Published: March 2018

The surface of printed paper has been examined through a fully automated attenuated total reflection (ATR) mapping technique. Automated z-axis control was utilized to bring the sample into contact with the ATR objective in a reproducible manner and an integrated mapping stage was used to position the sample. A force sensing device, the Contact Alert, was used to ensure optimal contact between the sample and internal reflection element Global manipulations of the resultant data revealed compositional differences attributed to the printed ink, carbonate and cellulose distributions. These differences were clearly evident in the infrared, but not discemable in the visible. The bulk filler Kaolinite was identified as a post processing contaminate as well as a trace mixture of Dioctyl Phthalate and an aromatic acrylate.
SEM Processing Of Blood Samples
Authors: Miller Sara E
Published: March 2018

A long time ago, we ciid some work on RBC's from muscular dystrophy patients, We found that the cells are very sensitive to pH, salt concentration, glass, and other things (maybe including the moon???), Low pH, increased salt, especially NaCl, and sitting in a glass tube or on a glass slide unfixed would cause echinocyte formation.

We got around the problem by drawing the blood and then IMMEDIATELY dropping (drop by drop) blood samples into 1% glutaraldehyde in phosphate buffer, pH 7.4 (not PBS). You can use a Maunsbach formula, where 0.135 U P04 gives 300 milliosmoles, or 0.1 M P04 plus sucrose (try 1.8 % sucrose). Test the osmolarity of the buffer; it should be 300 ± 10 or so. The final osmolarity of the buffered fix will be 400 milliosmoles; 300 from the buffer and 100 from the glutaraldehyde! The fix should be room temperature (not cold) when the blood is added. It can be stored refrigerated.
Resolution and Resolving Power
Authors: Anderson Ron
Published: March 2018

A very basic point that is almost always overlooked when discussing SEM “resolution,” is the difference between “resolution” and “resolving power.”

An SEM might have a resolving power of 1 nm or so based on the observation of gaps between gold particles on a featureless carbon film. Fine—if ones job is to look at gold on C.

For the actual 3-D samples most everyone looks at, EVERY micrograph has a DIFFERENT resolution, closer to 10 nm, because of secondaries generated by back scattered electrons, edge effects, …etc. If you want resolutions closer to the instrument's resolving power you have to look at thin TEM specimens without sharp edges and angles.

In our semiconductor lab we have several FESEMs advertised to have resolutions of 1 nm that can not resolve 4 and 5 nm layers in a film stack.
Cleaning Platinum Crucibles
Authors: Bigelow Wilbur C
Published: March 2018

Many years ago we regularly used platinum crucibles in many analytical chemistry procedures, and according to my analytical chemistry book, platinum can be cleaned by fusion with potassium or sodium bisulfite. I later adopted this procedure with good success to clean the platinum apertures for an RCA EML electron microscope.

Get asmall ceramic crucible, put a bit of the bisulfite in it, heat it until the bisulfite melts, then drop the apertures into the melt. After a few minutes allow the melt to solidify, dissolve the bisulfite with hot water, and your apertures should be as bright and shiny as new.
Preparing Powders For Electron Diffraction Studies
Authors: Walck Scott D
Published: March 2018

Questions often come up concerning the best way to prepare powders for electron diffraction analysis in the TEM. This is actually fairly simple:

1) Take an oxide powder, grind it up with mortar and pestie and take a carbon coated grid and swipe it across the fnes. Two glass slides can also use to grind up the powder. 2) A number of materials can be evaporated onto a carbon coated grid or onto a cleaved NaCI sample and then float that off on water onto a grid. 3) A molybdenum wire can be smoked in air to provide crys tals. If the wire is left in the smoke long enough, there will probably be enough crystal to cover a grid. Heat the wire across the terminals of an evaporator or heat with a torch to generate the white smoke. Thus MoO3 sample will pro- vide a good rotation calibration sample. Magnesium can also be burned to produce MgO crystals.
Deblurring Images
Authors: Ramer Everett R
Published: March 2018

If you are an optical microscopist, chances are you have sometimes wished for a way to increase the depth of focus of your images. In this article I describe a method that does this using a simple combination of functions built into most image processing software - so it will not cost you very much to try, The method, however, is not universal and some trial-and-error will be required to get it to work in different applications. Finally, this method is not limited to microscopy and will work with any imaging system.

The basic steps for creating an image with a large depth of focus are straight forward:

1. Take a series of images at different focal planes 2. Remove the blurred content from each image 3. Combine the debiurred images into a single image
Instructions for Safe Use of Microscopes
Authors: Ryan Keith P
Published: March 2018

Looking through a microscope for extended periods is not what we were designed for - it requires holding our bodies in an unnaturally rigid position. This can cause cramped muscles and strained tendons and ligaments in the head, neck, back, shoulders, arms and wrists, Also, repetitive movements associated with microscope work can cause strain injuries. There are specific health and safety regulations for computer use. Yet, you are tied much more to a microscope than to a computer, because of the eye-piece requirements.

Main problem - microscopists know how to align their microscope but few align themselves! Many users are “slumpers”, and need training to avoid problems later.
Double Embedding in Cellulose Nitrate and Paraffin Wax, an Old and Useful Method that is Easily Misunderstood
Authors: Kiernan John A
Published: March 2018

Cellulose nitrate is also known as celloidin, collodion, low viscosity nitrocellulose (LVN) necoloidine, nitrocellulose, parlodion, pyroxylin, and soluble gun cotton. (Some of these are trade-names; for even more synonyms, see the Merck Index, under pyroxylin.) It is made by treating cellulose with a mixture of concentrated nitric and sulfuric acids, This converts some of the hydroxyl (-OH) groups of cellulose to nitrate ester (-ONO2) groups. The molecular size and physical form of the original cellulose and the proportion of nitrated hydroxyl groups determine the properties of the product. It is useful in microtechnique because of its physical properties and its unusual responses to solvents and other liquids.
Plugging A Small Hole
Authors: Carmichael Stephen W
Published: March 2018

It has long been appreciated that communication between the nucleus and the cytoplasm of a cell occurs through the nuclear pores. Regulation of this communication has remained a mystery. A breakthrough in our understanding of this regulation was recently presented by Carmen Perez- Terzic, Jason Pyle, Marisa Jaconi, Lisa Stehnc-Bittel, and David Clapham of Mayo Clinic. Using field emission scanning electron microscopy (FESEM), transmission electron microscopy, and atomic force microscopy (AFM), they demonstrated the presence of a small plug within the nuclear pore that was present under certain physiologic circumstances. This “plug“ may regulate the movement of molecules through the pore.
A Review Of The Development Of Scanning Electron Microscopy At High Chamber Pressure
Authors: Robinson Vivian
Published: March 2018

Ever since electron microscopes were developed, it has been the goal of microscopists to observe specimens in their natural state, free from artefacts which can often be introduced through specimen preparation. For most biological specimens, that includes the presence of water. With a pressure of 10-4 torr or lower required to operate a scanning electron microscope (SEM), liquid water, which required a pressure of above 5 torr, was clearly a problem.

Although several attempts had been made to examine hydrated specimens in a SEM, the first published results of water imaged in a stable and reproducible manner in the SEM, were presented at the Eighth International Congress on Electron Microscopy in Canberra in 1974 (Robinson, 1974).
Professional Scientists, Move Over. Here Come the Amateurs
Authors: Carlson Shawn
Published: March 2018

San Diego: Nestled in a small office in the Physical Sciences building at San Diego State University a new nonprofit group is challenging the Ivory Tower monopoly on scientific research. The Society for Amateur Scientists (SAS) is an unprecedented collaboration between professional and amateur scientists, and if they get their way, they will forever change how science gets done.

SAS is founded on the premise that it doesn't take a Ph.D. to do research. With the right support, they claim, even everyday people can make important scientific discoveries.
Atomic Force Microscopy for Biologists
Authors: Carmichael Stephen W
Published: March 2018

Atomic force microscopy (AFM) has proven to be very useful to material scientists and physicists. Biologists are only beginning to utilize the potential of this methodology. In a recent article, Tatsuo Ushiki, Jiro Hitomi, Shigeaki Ogura, Takeshi Umemoto, and Masatsugu Shigeno reviewed the applications of AFM to biologic studies.

They began by reviewing the basic principles of AFM, emphasizing the value of the non-contact mode for visualizing the relatively “soft” surface of biologic specimens. They presented some examples of biologic images: DNA, chromosomes, and collagen fibrils. The specimens examined with the AFM did not need to be coated, theoretically offering a view with a smaller potential for artifacts. AFM images have the advantage of containing quantitative information about the sample height.
True Colour SEM Imaging for Phase Recognition AMD X-Ray Microanalysis
Authors: Statham Peter J
Published: March 2018

Secondary (SE) and backscattered electron (BSE) signals in the SEM provide high resolution monochrome images. BSE signal strength is modulated by mean atomic number and ‘false” colour can be introduced to enhance material contrast. Colour can also be introduced using multiple SE detectors, each with a different sensitivity to topographic and compositional information: by controlling signal mixtures and colours, the operator effectively has access to a powerful “studio” to generate aesthetically pleasing colour images. In both these examples, the correspondence between local elemental content and colour is entirely arbitrary and under subjective control of the operator, Elemental x-ray maps can be acquired and combinations colour coded to reveal phase distributions. For large numbers of maps and images, chemometric techniques such as PCA may be used to discover common relationships and assist the process of colour coding. Images derived from x-ray maps are usually low resolution and the analyst has to decide which elements to include and do a fair amount of data manipulation before any conclusions can be drawn.
Big is Beautiful: Science (and Art) in Wood Microscopy
Authors: Chaffey Nigel
Published: March 2018

Notwithstanding the importance of trees, considerable technical problems have severely restricted study of the fine structure of the vascular cambium and the wood and bark that it produces. And despite the advent of immunocytochemical techniques, it is only in the last few years that the roie of the cytoskeleton in the process of secondary vascular differentiation has been studied. Yet, for those who persist with this intractable material, the experience can be rewarding. This article discusses the difficulties involved in microscopy of this material, and offers some solutions.
Calibrating the TEM
Authors: McCaffrey John P
Published: March 2018

An accurate calibration of magnification, diffraction patterns and the relative rotation between the two is critical in quantitative transmission electron microscopy (TEM). The manufacturers of TEM's supply magnification values for each image magnification step and each value of camera length for their instruments, but these values have been observed to be in error by up to 10%, These errors can occur due to variations in lenses in individual microscopes as well as through power supply variations and aging electronic components. Before attempting quantitative TEM analysis, a series of calibrations of the individual TEU should be undertaken.
Some Hints on Clinical TEM Negative Staining for Viruses
Authors: Miller Sara E.
Published: March 2018

I would not, repeat *not*, recommend fixing any virus sample before attaching it to the grid. If you are concerned with pathogenicity, you can fix it after allowing it to adhere to the grid, then wash with water and stain, or you can UV irradiate both sides of the grid after staining. For speed in reporting clinical results (we do almost 1000/year), we look at negative stains of potentially infectious material without fixing by keeping a separate specimen holder for "dirty" grids and another for nonpathogenic material such as sections. The grids are then UV irradiated before storage,
A Closer Look at Leaves
Authors: Carmichael Stephen W
Published: March 2018

All of us have looked at leaves. They're interesting. Some of us have looked at leaves under a light microscope. Still interesting. Some have looked at leaves under more powerful microscopes, and apparently they found it interesting still. Now some folks have looked more closely than ever before, and guess what? This may be the most interesting! Wendy Mechaber, Durwood Marshall, and Frances Chew of Tufts University, Richard Mechaber of GEI Consultants, Inc., and Renee Jobe of TopoMetrix turned to the atomic force microscope (AFM) to analyze the landscape of the surfaces of leaves, apparently for the first time.
A New Look at Old Beer and Bread
Authors: Carmichael Stephen W
Published: March 2018

We know from the pictographic history that the people in ancient Egypt were fond of beer and bread. Fortunately, they sent samples of these food items along with some of their more esteemed citizens to sustain them in the afterlife. Also, samples were available from rubbish heaps of ancient villages, allowing for the comparison of funerary goods with everyday foods. Additional luck was that the dry conditions have kept some samples from deteriorating even after thousands of years. Whereas they did leave us samples, they didn't leave recipes. There have been many theories about how they brewed and baked in ancient Egypt, but proof was lacking. Recently, Delwen Samuel of Cambridge University used optical and scanning electron microscopy (SEM) to determine how the ancient Egyptians brewed beer and baked bread.
Choosing Between Confocal Microscopes : A Fly-Eye's View
Authors: Lam Mark HC , Jans David A
Published: March 2018

We have recently been shopping for a confocal microscope and have found a simple way to test the capabilities of the various units that have been demonstrated to us. Some of the important aspects that we were looking for in our “ideal” multi-user system were:

1) Ease of use. 2) The ability to obtain good X-Y, X-Z and hence X-Y-Z resolution, and the accurate display of these images. 3) The depth within the sample at which the system can resolve structures (this of course depends mostly on the lenses used), but is still an important criteria as it reflects on the system as a whole. 4) “extras” such as a transmission detector and reconstruction/ analysis/image manipulation software.
Ultra High Speed Imaging System Helps Unlock Understanding of Dynamics of Operation in Microdevices …
Authors: Hofer Eberhard P , Rembe Christian , Honour Joseph
Published: March 2018

DRS Hadland, formerly Hadland Photonics, has supplied the Department of Measurement, Control and Microtechnology at the University of Ulm with an ultra-high speed digital imaging system to help them gain a greater understanding of the dynamics of moving parts in microdevices.

The measurement of position, velocity and acceleration of moving parts in microdevices is of great interest in the rapidly growing field of microsystem technology in order to solve the problems needed to allow evolution from laboratory use into industrial mass production. Such research is targeted towards gaining a better understanding of the dynamics of the moving parts in microdevices.

For the visual investigation of dynamics in microdevices high optical magnification is necessary because the dimensions of microsystem components are very small. Therefore, velocities of parts of such microdevices appear to be extremely fast and time constraints are very small.
Digital Imaging: When Should One Take The Plunge?
Authors: Mansfield John F
Published: March 2018

The current imaging trend in optical microscopy, scanning electron microscopy (SEM) or transmission electron microscopy (TEM) is to record all data digitally. Most manufacturers currently market digital acquisition systems with their microscope packages. The advantages of digital acquisition include: almost instant viewing of the data as a high-quality positive image (a major benefit when compared to TEM images recorded onto film, where one must wait until after the microscope session to develop the images); the ability to readily quantify features in the images and measure intensities; and extremely compact storage (removable 5.25” storage devices which now can hold up to several gigabytes of data).
The Advantages of Using a Videomicroscope for Classroom Teaching
Authors: Hedgepeth David J
Published: March 2018

To see what is general in whet is particular, and what is permanent in what is  transitory is the aim of scientific though …. Alfred North Whitehead

Science educators in K-12 schools are often confronted with skepticism when the budgetary needs for equipment and materials come up for discussion. They are expected to make science “interesting”, “exciting”, “motivating”, and “up-to-date”, but without investing money in modern technology. It is important to not let this common fascination with novelty, excitement and parsimony, prevent us from realizing the full potential for videomicroscopy in classroom science teaching. In addition to their “gee, whizl” aspects, videomicroscopes offer a number of instructional advantages that make them worth the money, and I will present some ideas about how to use and configure a videomicroscope for classroom use.
Preparation of Protein a Gold
Authors: Webster Paul
Published: March 2018

Colloidal gold has been used for centuries in the preparation of stained glass for windows and fine glassware. In recent years, colloidal gold particles have become a useful tool in microscopy for staining tissues and sections. Colloidal gold particles are especially useful for biological electron microscopy, Some of the reasons why are listed below.

* Homogeneous preparations of particles varying in size from 3μm to 20μm can be easily prepared. * Colloidal gold suspensions are inexpensive to prepare. Most proteins can be easily coupled to colloidal gold particles. * Most proteins can be easily coupled to colloidal gold particles. * Proteins coupled to gold particles do not appear to lose their biological activity. * The colloidal gold particles can be easily seen in the electron microscope. * Colloidal gold does not naturally occur in biological material. Therefore, if you see it, it is because you put it there. * Colloidal gold probes can be used for light microscopy, The larger gold particles can be directly observed by the light microscope. Small particles are detected by silver enhancement or epipolarized illumination. * The same probes can be used for both LM and TEM imrnunocytochemistry.
Nanoscale Thermal Property Characterization of Automotive Polymer Coatings
Authors: Germinario Louis T
Published: March 2018

This article discusses AFM-based localized thermal analysis of crosslinked polymer coatings based on a recent breakthrough in nanoscale thermal probe technology. Examples include the monitoring of the softening point of automotive clearcoat systems, as a function of cure time and cure temperature and characterization of degradation and embrittlement of weathered acrylic-polyurethane coatings. Comparison of nano thermal analysis with bulk DSC and MDSC is made and its inherent advantages over DSC in analyzing surfaces is demonstrated.
Computer Network Laboratory for Microscopy Education at the Materials Science and Engineering Department, The University of Arizona
Authors: Seraphin Supapan , Chandler Gary W , Switala Michelle S
Published: March 2018

We report here on the first year of development of a novel teaching facility which incorporates new techniques designed to reach new audiences without diluting subject content. Interactive computer software coupled with rich scientific content of microscopic images provides a unique opportunity to help students learn science and technology, the laboratory is comprised of twenty student workstations networked to various microscopes, thus expanding the number of students capable of "hands-on" data acquisition and analysis by twenty times. Two scanning electron microscopes (SEM), a transmission electron microscope (TEM), and several light microscopes (LM) are interfaced through a server to the workstations.
The MSA Placement Office
Authors: Watson John HL
Published: March 2018

The editor of Microscopy Today has asked me to write an article which describes the Placement Office of the Microscopy Society of America and I have accepted this opportunity to bring the history and operation of the Office to the attention of ms readers in what follows the word “Candidate” refers to a member of MSA who is in good standing and who has registered appropriately with the Placement Office as actively seeking a position or a change, and “Employer” refers to institutions or companies who have registered with the Office as having a position open.
More Than One Ever Wanted To Know About X-Ray Detectors Part VIII: If I Know It's There, Why Can't I See it?
Authors: Turner D Clark
Published: March 2018

This month we are going to deviate from Mark Lund's normal discussion and talk about one of the practical problems that must be considered when using an x-ray detector on a scanning electron microscope to solve real-world problems.

Several years ago I worked in the analytical laboratory of a major semiconductor manufacturer. One day a process engineer came into the lab and asked us to develop an analytical method to determine the amount of copper in an aluminum film on a silicon wafer. The levels of copper would be somewhere between 0.5% and 1.0%. He gave me a sample, saying that he didn't know the exact concentration of copper but was certain that it was at least 0.5%.
Multi-User Scanning Electron Microscope
Authors: Chumbley LS , Meyer M , Fredrickson K , Laabs F
Published: March 2018

Teaching a large number of students simultaneously to use a scanning electron microscope (SEM) has traditionally been difficult. A typical classroom scenario would be of one student seated in front of the SEM next to the instructor while the remaining students stand idly behind the operating student. The truth of the oft repeated sentiment expressed by microscopists, "There is nothing more boring than watching someone else do microscopy", would be proven time and time again in such training sessions as the uninvolved students would quickly lose interest and either fall asleep or talk among themselves.
A Scanning Probe Microscope in My Scanning Electron Microscope?
Authors: Collins George J
Published: March 2018

Scanning probe microscopes (SPMs) designed to fit into scanning elec- tron microscopes (SEMs) are now becoming commercially available and you might ask, "Why would I want to put an SPM in my SEM"? The primary reason is that the too forms of microscope are very complimentary. Each microscope extends the power of the other. The SEM can do things that are hard to do with an SPM, and vice versa.

Not long after the introduction of the STM and the AFM, a few re- searchers built custom SPMs and installed them in their SEMs. The reports of these projects to build hybrid microscopes and examples of the data they produced can be found in the scientific literature.