bluuebunny/crossref_metadata_2025 huggingface dataset:
Just Say NO to Microtoming Silicon!
Authors: Anderson Ron
Published: March 2018

Arecent discussion on the Microscopy Listserver on the subject of microtoming Si reminded many of us of this decades-old issue. Silicon is one of the easiest materials to prepare for TEM analysis with dozens of protocols available including chemical etching, electropolishing, mechanical polishing with and without ion milling, microcleaving, and the use of a focused ion beam instrument. The time involved in Si preparation can range from minutes to a few hours. Things become more complex if it is desired to prepare a Si semiconductor device with high specimen preparation spatial resolution i.e. prepping a prespecified, very small, structure.

Now and then a technologist, often times in the biological sciences, is asked to prepare a Si TEM specimen and wonders if Si can be microtomed. The results are almost always a pile of Si dust and frequently a damaged diamond knife.
Laser Capture Microdissection: A Punch Biopsy Under the Microscope
Authors: Carmichael Stephen W
Published: March 2018

The size and precision af a tissue sample has always been a concern. As it has become possible to analyze smaller and smaller samples with molecular techniques, one must be increasingly concerned that the sample is what we think it is. So how do you dissect out a specific cell or a small group of cells? Whereas several techniques have been suggested, a group at the National Institutes of Health (NIH) have come up with an ingenious solution. Robert Bonner, Michael Emmert-Buck, Kristina Cole, Thomas Pohida, Rodrigo Chuaqui, Seth Goldstein, and Lance Liotta have published a technique they have termed Laser Capture Microdissection (LCM).

With LCM, Bonner et. al. have demonstrated that a specific cell can be identified and transferred to an appropriate container for molecular analysis. Using the polymerase chain reaction (PCR), the genetic material from a single cell can be amplified for analysis. However, data from several cells (about 20) needs to be examined so that variations in the cell cycle, etc., can be averaged.
Safety Considerations Regarding the Use of Propane and Other Liquefied Gases as Coolants for Rapid Freezing Purposes
Authors: Ryan Keith P , Liddicoat Malcolm I
Published: March 2018

Liquid propane and similar coolants are used in the rapid freezing of biological specimens. These coolants form explosive gas mixtures with air with a 14,000-fold increase in volume over that of the liquid. The liquefied gases have high vapour pressures and, unless they are maintained below their flashpoint, the vapour above them will reach ignitable concentrations. The flashpoint of liquid propane is -104°C. Ethane has a higher vapour pressure, and vapour mixed with air above liquid ethane can be ignited at a coolant temperature of -130°C. The danger is minimized if the coolant is maintained near its freezing point and under a nitrogen atmosphere, in a fume cupboard. Liquid nitrogen evaporates to a 690-fold increase in volume at room temperature. It is important to ventilate the working area, especially when cryo-sectioning in a small room, otherwise there is a possibility of asphyxiation.
Negative Staining: Historical Background and Technical Development
Authors: Harris J Robin
Published: March 2018

There is a considerable body of information of a technical and review nature on negative staining elsewhere in the literature (Bremner et al., 1992; Harris and Home, 1991, 1994; Hayatand Miller, 1990; Holzenburg, 1988; Home, 1991; Nermut, 1991; Spiess et al., 1987; Valentine and Home, 1962); therefore, I shall attempt to avoid undue repetition and present the current laboratory approaches with which I am personally familiar and have achieved some technical success. After considering the range of procedures necessary for the production of carbon and carbon-plastic support films (sometimes termed substrates) emphasis will be placed upon the droplet negative staining technique (Harris and Agutter, 1970; Harris and Horne, 1991). I was introduced to this approach by Ennio Lucio Benedetti in his laboratory, at the start of my doctoral studies in 1966 (Anderson, 1966; Benedetti and Emmelot, 1965,1968) and with minor variations it is still useful for many biological applications.
Slide Preparations: Heater for Mountants
Authors: Denko James
Published: March 2018

In the past, I have used mountants such as DIATEX (which is a synthetic mountant of 40% acrylic resin solids, and 60% toluene), or Canada Balsam in xylene for general purpose mountants. If a tight seal of resin forms around the coverslip, the prep is usually good for some time and may last indefinitely. However, the center of the prep still contains resin mixed with solvent that has not had a chance to evaporate, If the solvent continues to evaporate slowly from the prep, large air bubbles will replace the solvent and ruin the prep.
A Fast-Result Method of Planar Polishing for Optical Microscopy
Authors: Rubin Joseph , Hazeldine Tim
Published: March 2018

The planarizing technique of materials lapping and polishing shows many benefits in providing samples for optical microscopy in failure analysis, quality control and related fields. A method is described below which provides both rapid and accurate micro-sections of pcb's, wafers, packaged components and other processed materials, with the use of a novel approach involving a 'calibrated' polishing base and a 'Micropositioner' head. Other benefits include the ability to halt material removal at a predetermined process endpoint and convenient sample mounting techniques.
Warthin-Starry Stain for Spirochetes in Tissue
Authors: Czubek Anne
Published: March 2018

I had recently been involved in a computer group discussion about the Warth in-Starry stain. No one seems to like to do it, except me. Here is a procedure that my histology laboratory (The Toledo Hospital, Toledo, Ohio) received from Lee Luna, who was a consultant to our laboratory, just before his death, Any "tips-of-the-trade" I have added.
Toward Quantitative Defect Analysis Using HREM
Authors: Smith David J
Published: March 2018

The electron microscope has evolved to the level where it is now straightforward to record high-resolution images from thin samples (t~ to 20 nm) that are directly interpretable in terms of atomic arrangements. Whilst recorded images necessarily represent two-dimensional projections of the structure, many defects such as dislocations and interfaces may be linear or planar in nature and this might be expected to be amenable to detailed characterization. In this review, we briefly consider the recent significant progress that has been made in quantitative defect analysis using the high-resolution electron microscope and then discuss some drawbacks to the technique as well as potential scope for further improvements.
EM Site A.C. Magnetic Field Sources, Surveys and Solutions Part V : Solutions!
Authors: Dunnam Curt
Published: March 2018

This month's installment completes our primer series on magnetic fields by defining conditions where remedial EM site shielding is in fact technically feasible and by illustrating examples of both passive and active shielding methods (or attaining lower site fields. For those readers who may have missed one or more previous articles, we have thus far presented some basic physics describing magnetic source fields [Microscopy Today, November, 1995), examined magnetic survey equipment and methods relevant to EM interference thresholds (Ml, January, 1996), and, in Part IV (“Survey Data Analysis”, MT, May, 1996), suggested techniques for interpretation of typical EM site survey data.
Light Microscopy Criteria for Electronic Imaging
Authors: Clarke Theodore M
Published: March 2018

Industrial laboratories have traditionally used 4” x 5” (100 x 125 mm) photomicrographs. Polaroid 4” x 5” prints have largely replaced glass plate and sheet film contact prints in industrial laboratories. High resolution 2000 by 3000 pixel imaging systems should be able to match the resolution of the 4” x 5” photomicrographs, typically 6 cycles per mm at a magnification of 500 times N.A., with a significantly larger field size which better utilizes modern, wide field optics. CCD cameras with 1024x 1280 pixel sensor arrays should be able to essentially match Polaroid 4” x 5“ photomicrograph prints in field size and resolution.
SEM Provides Critical Process Information in Pharmaceutical Applications
Authors: Lich Ben
Published: March 2018

A number of trends in pharmaceutical manufacturing are driving rapid growth in the use of scanning electron microscopes (SEM) for high-resolution imaging and analysis. At the same time, continued development of SEM technology is enhancing system performance while simultaneously reducing usability barriers that have historically limited the acceptance of these techniques in pharmaceutical applications.

Among the most significant industry trends is a concerted effort by governmental regulatory agencies to encourage improvements in pharmaceutical manufacturing processes by applying the same scientific principles and engineering techniques that have lead to successful improvements in other industries, notably automobiles and semiconductors. The exceptionally high requirements for product quality within the pharmaceutical industry have generated a regulatory regime that imposes prohibitively high costs in both time and money to gain approval for process changes, even though the changes result in substantial performance gains.
Reconstructing What Was: Software Applied To Serial Section TEM
Authors: Feinberg Marcia D , Fiala John C
Published: March 2018

The well-known recipe for serial reconstruction in microscopy consists of the following six steps: fix and embed specimen, cut and mount sections for microscopy, image sections, align images in the computer, identify and trace profiles in images, generate three-dimensional (3D) visualizations. The free software program Reconstruct facilitates the final steps of this process for many types of microscopy, including scanning electron or ion beam microscopy applied to material and light microscopy applied to biological samples. We describe here how serial sectioning and transmission electron microscopy (TEM) can be combined with the Reconstruct software to generate large volumes of soft tissue ultrastructure for analysis.
Plasma Cleaning EM Stages, Specimens, and Columns
Authors: Zaluzec Nestor
Published: March 2018

In my 20 plus years of experience, I have found that nearly every specimen contaminates to some degree (some slower, some faster) in an electron microscope regardless of the manufacturer. Most of this contamination comes from the specimen, and it's magnitude is a function of the sample (metallic, semiconductor, organic, etc.), the method of preparation (electrochemical chemical, microtoming, ion milling, etc.), the microscope conditions, the probe and probe current - plus a number of less well controlled factors. Reactive gas plasmas can fortunately be used to mitigate the contamination process and frequently reduce the problem to negligible levels. Basically, one places the specimen/stage in a “tow energy plasma” where the gas acts like a catalyst for a localized surface chemical reaction, The energy of the plasma breaks weak bonds of the hydrocarbon compounds on the surface which then make these species somewhat volatile so that they can further react with the gas in the plasma.
How Is The Cytoskeleleton Involved In Mechanical Signal Transduction?
Authors: Strum Judy M
Published: March 2018

The underlying mechanisms whereby cells sense and respond to external stimuli are not well understood, but for some time it has been known that the extracellular matrix has an influence on the behavior of cells. For example, changing the flexibility and/or adhesiveness of the matrix can change the shape of cells, and determine whether or not they continue to divide or begin to differentiate. Recently, in a series of elegant experiments, a group of cell biologists in Boston have demonstrated the presence of an interconnected molecular network pervading the entire living cell, extending from its outer surroundings into the genes in its nucleus.
The Database Solution to Particle-by-Particle Analysis of Mixed Mineral Dusts
Authors: Strohmeier BR , Bunker KL , Harris KE , Hoch R , Lee RJ
Published: March 2018

This work involves the development and application of a database for the morphological, crystallographic, and chemical characterization of amphibole particles that occur as accessory minerals in the former vermiculite mine in Libby, Montana. The data in the database were collected using transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM) techniques for particle-by-particle characterization of mixed mineral dust samples.

In the fall of 1999, public attention was focused on the small town of Libby due to health concerns over potential amphibole asbestos exposure that occurred in the now closed vermiculite mine. The vermiculite deposit, located in the Rainy Creek Igneous Complex, about seven miles northeast of Libby, was discovered in 1913 and commercial production of vermiculite began in 1923.
Microscopy for Children
Authors: Schooley Caroline
Published: March 2018

Is there's a child in your life? Are you thinking about giving a microscope this holiday season? DO IT! But please think carefully about what you buy. You’re reading Microscopy Today, so you use some sort of microscope professionally; you may be tempted to give the youngster a lab-quality hand-me-down. DON’T! The complexities that you take for granted will only intimidate them. The youngest child will enjoy a magnifiying glass. I still remember the pocket-flashlight-style microscope that I had when I was young; I took it everywhere. After that, the best “first” microscope is a monocular dissecting scope; you can consider a very basic compound microscope later, in the middle school years.
The Blind Showing The Way To The Sighted
Authors: Revel Jean-Paul
Published: March 2018

When one speaks of microscopes one usually imagines devices which produce spatially resolved images. So it is most intriguing when a novel application of microscopic techniques permits discoveries not by forming images but by allowing very precise measurements to be made on very small objects. The blind showing the way to the sighted! A recent paper in Nature is a good example of what I speak. It deals with biological motors, which, as cell biologists are learning, are involved in the movement of cells and the movements of organelles within cells. There are a number of different biological motors, but all are molecules which change shape, as they convert the chemical energy derived from the hydrolysis of high energy molecules such as ATP, into mechanical work. As the motor molecules undergo this conformational change and then return to their original state they take a step away from their starting point, dragging along the structures to which they are attached.
Video Microscopy
Authors: Rawlins DJ
Published: March 2018

There has been a tremendous expansion in the use of video in microscopy in recent years. This is probably not due to the most obvious advantage of video, that of real-time imaging of moving events, but to its use in image analysis systems. The cheapness of PCs and the associated hardware and software to store and manipulate images, coupled with the availability of lowcost CCD cameras has made the analysis of microscope images commonplace. In the article the equipment used and the sorts of analysis which can be performed will be briefly outlined. The standard text on video is that of Inoue; a more recent review is by Weiss et al. while the major video equipment manufacturers will also provide literature and advice on the more up-todate equipment.
Issues in Cathode Performance Part 2 - Cathode Mounting Design
Authors: Heer Damon
Published: March 2018

LaB6 and CeB6 cathodes are widely used as high-brightness, highstability, long-lifetime cathodes in a variety of electron beam appiications. Two of these factors - stability and lifetime - are critically dependent on proper cathode-mounting design.

When the benefits of LaB6 as an emitter material were first investigated, the LaB6 was indirectly heated by an electron bombardment coil. This design was cumbersome and did not perform well. Wire mounts, such as those used for tungsten emitters, were developed (and are stili used today); however, they have many drawbacks. Their stability and lifetime are limited because the thin wire mount moves easily and will eventually break under the changing temperature conditions encountered during operation.
Digital Imaging for TEM - Part III Characterizing Digital Images
Authors: Buonaquisti Anthony D
Published: March 2018

Last months issue of this publication contained the second article article in this series on digital imaging far TEM - and listed factors that may be stimulating the recent interest in digilal imaging for TEM. Most of the factors are concerned with issues of functionality. A digital imaging system can enhance TEM operation, image storage, image processing and communication. Significantly, the surge in interest was not linked to claims that digital images have better detail than images captured using sheet film. This is a pivotal issue for some microscopists. Nevertheless, my experience has been that many rnicroscopists, even skeptical microscopists, are surprised at the quality of output from a modern digital imaging system when using a high quality output device to produce hard copy images.
Use of Floor Polish in Mounting Sections for Light Microscopy
Authors: Imel Kevin M
Published: March 2018

Over the years a number of methods have been described to mount tissue sections on glass slides (for example see Humason 1979). This paper presents a novel mounting medium that is inexpensive and readily available at the nearest grocery store - floor polish. This floor polish is available under a variety of trade names (e.g., Brite® and Future® both from S.C. Johnson and Son. Racine, WI) labeled for use with "no-wax" floors. It has been found that this product is well suited to use as a mounting medium for both gelatin/albumin embedded sections as well as epoxy sections. The floor polish has demonstrated a much lesser degree of tissue distortion in some tissues as compared to the mounting media previously used in our laboratory, including Permount® (Fisher Chemical, Fair Lawn, NJ) and 30% sucrose in distilled H2O.
Three Hundred Years After Hooke and Van Leeuwenhoek: Optical Microscopy in the Twenty-First Century
Authors: Isaacson M
Published: March 2018

We are always trying to extend our vision through the four senses of sight, sound, touch and smeil. The microscopy devised by Hooke and Van Leeuwenhoek more than three centuries ago are examples of methods used to extend our visible vision, in fact, instrument designers since then have constructed microscopes using each one of our senses to give us peeks into the microworid. When Robert Hooke took some scrapings from his teeth and viewed the bacteria in these scrapings in his primitive microscope,1 a whole new view of the world ensued. It would, however, have been difficult to predict how microscopy would evolve in the following centuries.
The Mystery of the Turin Shroud
Authors: McCrone Walter C
Published: March 2018

In 1355, or close thereto, a 3-foot wide and 14-foot long linen cloth suddenly appeared in history. Greeted rapturously by millions of Christians, it has maintained its acceptance as the true Shroud of Christ from 1300 years earlier. In 1978, a group of about 30 U.S. scientists and engineers studied the Shroud in great detail. All but one concluded the cloth is the burial Shroud of Christ.
A Novel Approach to Reembedding Thick Resin Sections for Ultramicrotomy
Authors: Imel Kevin M , Helmick Consetta M , Bailey J Franklin
Published: March 2018

In transmission electron microscopy (TEM), it is often desirable to focus our attention on certain cells or structures that are sparsely distributed throughout a large tissue block. One method that is often used is to serially section through a large tissue block and then scan each thin section on the TEM for the cell or structure of interest. A much simpler and far less tedious method is to cut thick sections of the resin block, screen the sections using light microscopy for the cells or structures of interest and then somehow reembed only those sections with the cell or structure of interest so that they can be thin sectioned for TEM.
Depth Information Available from the Backscattered Electron Signal
Authors: Robinson VNE
Published: March 2018

Although the secondary electron (SE) signal is still the most commonly used signal in scanning electron microscopes (SEMs), the backscattered electron (BSE) signal is now in wide use. Imaging both atomic number and surface topography have been the major applications of BSE detectors, with some applications in channelling, magnetic contrast and similar specialized applications. Over the last few years, low voltage BSE imaging has been used for imaging surface features to a depth of a few nm. But the BSE signal contains much more information and new techniques are being developed to take advantage of its versatility.
Tricks and Treats in Photomicrography
Authors: Zieler H Wolfgang , McCrone Walter C
Published: March 2018

Success in photomicrography depends, not only upon the acquisition of a technique, but also upon the selection of equipment. Unless the equipment is provided with certain facilities and controls, it is impossible to create optimum final image quality in the object plane.

We shall direct our attention to that part of the equipment which - next to the performance of objective and eyepiece - has the greatest influence upon the quality of the image, viz., the illumination system.
More Than One Ever Wanted To Know About X-ray Detectors Part IV: Windows for Elements Heavy and Light
Authors: Lund Mark W
Published: March 2018

I attend a local entrepreneur's luncheon once a month. Since the small town 1 live is the home of Word Perfect Corporation, and Novell, inc. is just down the road, you can imagine that mamy members are doing exciting things with software. When I tell them that MOXTEK makes windows (or X-ray detectors they really light up, until I tell them that! mean real windows.

X-ray detectors are used in electron microscopy to add chemical element analysis to the imaging capability of the microscope. A typical energy dispersive spectrometer uses a silicon crystal about the si2e of a shirt button to detect and measure the energy of incoming X-rays.
Seeing is Believing
Authors: Rochow TG
Published: March 2018

Since the first century A.D., mankind has found ways to see better1. During the next twelve centuries, convex lenses were made from clear minerals for eyeglasses, in order to overcome far-sightedness. Then, in the 1300's, clear, artificial glass became available for the same purposs. By the sixteenth century, concave lenses were made for the near-sighted. It was not until the 17th century that a combination of lenses led to the sciences of astronomy and microscopy.

One of the earliest important microscopists was the Englishman Robert Hooke (1635-1703). He owned a compound microscope with an objective lens and an eyepiece, much like Galileo's telescope.
Collecting Material For Specimen Preparation
Authors: Sanderson JB
Published: March 2018

Most workers wishing to prepare material for microscopy will study a limited range of organisms, and already be familiar with raising, culturing or collecting the species in question because of their research interests or adopted field of study. For those new to microscopy who have not yet defined a field of interest, it is suggested that they read a practical introductory text such as that of Grave (1991).

The diversify and abundance of animal, plant and microbial life available for collection means that gathering material can be a relatively simple task. Nevertheless, a methodical approach ensures that specimens are less likely to suffer damage and full details of their natural habitat are known, which will place any serious study into scientific context.
Using the Atomic Force Microscope to Measure Roughness Characteristics of Acetabular Prosthetic Shells Used as Hip Socket Replacements
Authors: Jani Shilest , Williams Gary , Marchese-Ragona Silvio P , Briggs Christie
Published: March 2018

Total replacement of a diseased or traumatized hip joint is fast becoming one of the most common surgical procedures. The acetabular prosthetic shell is gaining widespread acceptance as a socket replacement for this procedure. Bio-materials research is providing a wealth of information regarding the life span, wear characteristics, and performance of these replacements, with a major clinical finding being the destruction of bone (osteolysis) at interfaces with the implants. Osteolysis is widely thought to be associated with the particulate wear debris released from articulation of the ball and socket. Formation and release of these particulates will depend not only on the relative motion occurring but also on the surface roughness of the replacement materials.
Molecular Microspectroscopy: Where are we and where are we going
Authors: Reffner John A
Published: March 2018

Molecular microspectroscopy is the application of infrared or Raman spectrascopy, combined with light microscopy, for chemical analysis on the microscopic scale. For over a decade infrared microspectroscopy (ISM) has been an expanding technology both scientifically and commercially. Micro- Raman spectroscopy has a long history of scientific accomplishments with limited commercial success. Both of these techniques give spectral data that can be related to the bonding, crystalline state, isotopic content and molecular orientation of a material, but not its elemental composition.
Mounting and Storage Specimens
Authors: Goodhew Peter J
Published: March 2018

Specimen support grids are now almost universally 3.05 mm in diameter, except for a few high resolution stages and some very old instruments. They are available in a vast range of materials and designs. One catalogue lists 86 types in a total of 10 materials. The reason for this proliferation is to enable one to control the following:

(a) the amount of support the specimen needs (unsupported areas range from 20 pm to 1 mm in extent); (b) the material of the grid, so that it neither interferes with X-ray analysis nor reacts with the specimen; (c) the labeling of specific regions of a specimen (many grids have identification marks for relocation of interesting fields).

The cheapest most widely used supports are copper grids at a spacing of 100 bars in"1. Most grids have a shiny side and a dull side. Opinions differ as to the best side on which to mount the specimen but if a consistent practice is adopted it is always known which way up in the microscope the specimen was mounted.
Sources and Remedies of Phototoxicity in Live Cell Microscopy
Authors: Hockberger Philip
Published: March 2018

During the past decade there has been remarkable progress in understanding the behavior and function of biological cells. Progress was accelerated by the development of microscopic imaging techniques and fluorescent dyes that allowed investigators to visualize dynamic processes within subcellular compartments in heterogenous populations of living cells. These capabilities led to exciting new discoveries in cellular and molecular studies of a wide variety of cell types.

Efforts to study living cells under microscopic conditions are not without problems, however. The most vexing problem is phototoxicity caused by either illumination alone (endogenous toxicity) or illumination of fluorescent dyes loaded into cells (exogenous toxicity). In this report I provide an overview of these general types of toxicity as well as describe recent results that may shed light on how to reduce them.
A Comment on Formalin Safety
Authors: Dapson Dick
Published: March 2018

For several months there have been recurring threads on microscopy-related internet listservers concerning health and safety issues that have troubled us greatly at Anatech Ltd. The general theme has been to make light of toxicity claims, provide anecdotal comments about having survived many decades of working in labs, and giving the impression that current health and safety regulations are at best a pain and probably are the cunning products of misguided governmental agencies.

The great hazard of formaldehyde is not its proven carcinogenicity. Anyone interested in formaldehyde's effects on humans should read the preamble to OSHA's Formaldehyde Standard (Federal Register 52(233):46168-46312; December 4, 1987). According to studies cited therein, formaldehyde has been directly implicated in causing tumors in the lungs, nasoand oro-pharynx and nasal passages of humans occupationally exposed to levels of formaldehyde not unlike conditions existing in histology laboratories a few decades ago. Repeated and prolonged exposure increases the risk.
More Than One Ever Wanted To Know About X-ray Detectors Part V: Wavelength - The "Other" Spectroscopy
Authors: Lund Mark W
Published: March 2018

The use of x-ray spectrometry in electron microscopy has been a powerful market driver not only for electron microscopes but also for x-ray spectrometers. More x-ray spectrometers are sold with electron microscopes than in any other configuration. A general name for the combination is AEM, or analytical electron microscope, though in modern times AEM can include other instrumentation such as electron energy loss spectroscopy and visible light spectroscopy. In previous articies I have discussed energy dispersive spectrometers (EDS). These use semiconductor crystals to detect the x-rays and measure the energy deposited in the crystal. A second type of x-ray spectrometer measures the wavelength of the x-rays, and so is called "wavelength dispersive spectrometry" (WDS).
SEM Demonstrations for Younger Visitors
Authors: Lyman Charles , Repa Kathleen
Published: March 2018

Each year we show hundreds of students and visitors magnified images of common objects in our SEM. the best samples to use in SEM demonstrations for children are those which have detail that can just barely be seen with the naked eye or with a light microscope. Ideally, the sample would be something with which the child is already familiar, and one which can be explored at several different magnifications.

The simplest specimen is a penny attached to a stub by carbon or silver dag. Mount the coin such that the back side, showing the Lincoln Memorial, faces upward As shown in Figure 1, the statue of Lincoln inside the memorial can be seen with the naked eye.
The Great Polarized Light Microscope and the Great Salt Lake
Authors: McCrone Walter C
Published: March 2018

Teaching on-site courses for the McCrone Research Institute has enabled me to see a lot of the USA. The van and I have been to all of the states except Hawaii and Alaska besides all of the Canadian provinces except Newfoundland and the Northwest Territories. Some parts of the USA have become nearly as familiar to me (and van) as the Outer Drive in Chicago, Rte. 1 down the California coast, Rtes. 80 and 90 to New York and New England, 55 and 65 South, 40 Southeast to Los Angeles and 80 to Salt Lake City and San Francisco, in particular. The latter route across the Great Salt Lake Desert is one of my favorites. That route is always different because of the Great Salt Lake. It's a large lake under normal conditions but conditions are never normal.
Out of this World!
Authors: Carmichael Stephen W
Published: March 2018

If you have been hibernating for several weeks you may have missed the headlines and magazine covers exclaiming about “Life on Mars!” The basis for all of this excitement is an article in Science by Dr. David S. McKay of the Lyndon B. Johnson Space Center in Houston and eight of his colleagues from several academic institutions. The reader of this column will not be surprised by the fact that microscopes were used to detect evidence of life on a meteorite from Mars.

The first consideration was whether or not the meteorite was in fact a fragment of the martian surface. The specimen, known as ALH84001, is from a class of meteorites that appear to have resulted from impacts on Mars, some of the specimens landing in Antarctica where this one was recovered. Trapped gases (in glass droplets and stringers) in several of the family of meteorites closely match the martian atmosphere for several gases over 8 orders of magnitude range in abundance. Whereas ALHB4001 did not contain such trapped atmospheric gases, its elemental and isotopic composition closely resemble the meteorites that do.
Success in Science Reflections of a Retired Scientist
Authors: Mollenhauer Hilton H
Published: March 2018

The recent note by J.D. Watson in Science (1993) is another of the periodical advice columns in which someone of renown gives his or her perspective of how to succeed in this most difficult of fields. And a very good article it is. I find no fault with any of the four rules presented which I quote as follows: 1) “To succeed in science you have to avoid dumb people.” 2) “To make a huge success, a scientist has to be prepared to get into deep trouble.” 3) “Be sure you always have someone up your sleeve who will save you when you find yourself in deep s—.” 4) “Never do anything that bores you.” Unfortunately, these four rules are directed to a level of scientist that clearly bypasses most of us irrespective of how many good intentions we may have. Therefore I feel obliged to submit a revised list of thoughts for us average beings who plow through the days in an average research environment.
SEM Image Sharpness Analysis
Authors: Postek MT , Vladar AE
Published: March 2018

Fully automated or semi-automated scanning electron microscopes (SEM) are now commonly used in semiconductor production and other forms of manufacturing. The industry requires that an automated instrument must be routinely capable of 5 nm resolution (or better) at 1.0 kV accelerating voltage for the measurement of nominal 0.25-0.35 micrometer semiconductor critical dimensions. Testing and proving that the instrument is performing at this level on a day-by-day basis is an industry need and concern which has been the object of a study at IMIST. The fundamentals and results are discussed in this paper.
The Colors of Silicon
Authors: McCaffrey John
Published: March 2018

When silicon samples are thinned and backlit, they display a series of colors; from deep red in the thicker (-5-10 μm) regions, to orange and yellow in thinner regions, to effectively transparent in the thinnest regions, This colorful effect can be used as a technique for monitoring the thickness of cross-sectional samples prepared for transmission electron microscopy (TEM).

As seen in Figure 1, a cross-sectional TEM sample of a thin, indium tin oxide (ITO) film on glass was being investigated, A sample was prepared for low-angle ion milling by the Barna method with the addition of an adjacent piece of silicon for a thickness indicator. The colors of silicon could then be monitored to indicate when the ITO/glass sample was thin enough for TEM examination. In the figure, the arrow indicates the region of interest on the ITO/glass sample. This figure was produced by photographing the entire TEM sample through an optical microscope, backlit with a standard quartzhalogen illuminator.
Quantitation in Immunohistochemistry: a Response
Authors: Allison Russ
Published: March 2018

I have read with great interest the considered article by Dr, Barry Rittman (Microscopy Today#98-8, October, pp 8-9). In describing the difficulties of quantitation in immunohistochemistry, Dr. Rittman has gone to great lengths to give an authoritatively balanced view. It is, therefore, with some trepidation that I raise a few issues which may remain unresolved.

Dr. Rittman provides a list of criteria to be considered before applying quantitative analysis to this method. I would place the question of relating color developed to the amount of substrate present higher than number 7 on the list. To the best of my knowledge, there is little evidence that immunocytochemistry is stoichiometric, i.e.,that there is a relationship between color developed and amount of substrate present, indeed many consider that it is not, which represents a serious drawback.
Combined Confocal Imaging Reveals Interesting Complimentary Information
Authors: Foster Barbara
Published: March 2018

Recently, a question surfaced on the Microscopy list server regarding preparation of insect eggs for EM evaluation. While the electron microscopy approach involved considerable sample preparation (mounting, coating, etc.), our experience indicated that, for some of these applications, a combination of reflected and fluorescent confocal microscopy provided valuable information with little or no sample preparation required, provided there are not other considerations such as the extended resolution provided by electron microscopy.

In the biological arena, most confocal work is done in fluorescence mode, There have been some forays into imaging silver-stained structures using reflected light confocal but those applications have not been very prevalent in the literature. With the judicious addition of a quarter wave plate (a polarizing accessory) in the light path, the disruptive artifact from the laser beam can be removed from the image, converting any confocal into a dual purpose instrument.
The Next Generation of TEMs
Authors: Williams D B
Published: March 2018

A selection of the more common questions arising during a typical lab course for materials majors learning to use a TEM is as follows

1) Why must I insert the objective aperture, which governs image contrast, in the diffraction plane? 2) Why must I insert the selected area diffraction aperture, which governs the diffraction pattern contrast in the image plane? 3) Why is the TEM relatively useless if both apertures are in at the same time or both are out? 4) Why is the contrast in my images always greatest when the beam is parallel - which makes the screen intensity so weak, I sometimes can't see the contrast anyhow? 5) Why, when I need to record a diffraction pattern, do I have to learn to estimate exposure time from the analog screen, rather than just push a button and get a correct exposure, as in most other optical instruments and cameras?
Perfect Eyes
Authors: Gardner Lynn MG
Published: March 2018

It is extremely difficult to remove artifacts common to eye tissue such as folds, shrinking raisin effect, and parched earth effect. By adjusting our fixation and processing procedures, we attempted to reduce or eliminate these artifacts. We tested the fixatives from various vendors to determine which of them is most compatible with eye tissue and which would eliminate artifacts. We found Pen-Fix (alcoholic formalin; Richard Allen, Richland, Ml) produced optimal fixation (well defined nuclear detail, without bubbling artifact). In similar testing, we found Peel-a-way (Shandon-Lipshaw, Pittsburgh, PA) to be the optimal paraffin for processing and embedding ocular tissues.
Air Tables Are Not Always Needed for Vibration Isolation
Authors: Moss Anthony G
Published: March 2018

Most of the time an air table is not needed for vibration isolation of electrophysiological equipment and microscopes. In fact, an air table can be a liability in that it is likely to pick up air-borne vibrations. This is especially likefy if you have a solid enclosure, as is often used for the construction of Faraday cages used in electrophysiological investigations of vision research. Sound propagation can be particularly annoying, especially at the lower frequencies. Such important details are often forgotten in discussions of this topic.

A good damping table will help reduce the resonances, but still often can't overcome the difficulty posed by sound. One of the best solutions is proper placement of the entire rig: on the slab in the basement in a quiet place with no heavy vibrations from nearby heating, ventilating, and airconditioning (HVAC) and other equipment.
Emission Myths
Authors: Schamber Fred
Published: March 2018

Most electron microscopists appreciate that proper operation of the source is vital to the operation of the entire instrument. But because the gun involves a complex interplay of phenomena, few of which can be directly observed, some common misconceptions have gained currency. Typically these myths contain a kernel of truth, but they can also mislead when accepted uncritically. In this series of articles, we explore three areas of common misunderstanding relative to operation of the thermionic (tungsten filament or LaB6) gun. Field emitters are subject to very different considerations.
Measuring Electron Intensities from Film
Authors: Lamvik Michael
Published: March 2018

Measuring electron intensity is sometimes a useful thing to do as a part of an electron microscope study. The electron intensity recorded through a sample is one of the important pieces of information needed in determining the thickness of a thin film or the molecular weight of biological structures by electron scattering methods. Modern digital imaging systems in transmission electron microscopes allow relatively easy determination of electron intensities, but some labs don't have the expensive digital systems. Photographic film has been used traditionally to record electron microscope pictures, and film can record a very high density of spatial information.
The Tension Mounts: Will this be the Year for the First Commercial X-Ray Microcalorimeter?
Authors: Compton Bob
Published: March 2018

With the upcoming Microscopy & Microanalysis Conference only a few weeks away, the question that is in the mind of many industry experts is: “Will this be the meeting where the first commercial x-ray microcalorimeter is introduced?” If it is, you can bet your bottom dollar that there will be a major upheaval in the high resolution x-ray EDS business because of the ten- to fifty-fold improvement in X-ray resolution promised by this extraordinary device.
Looking at Slow Axonal Transport
Authors: Carmichael Stephen W , Stephen Brimijoin W
Published: March 2018

Neurons are about as polarized as cells ever get. Their axonal process can extend a distance that is up to a million times the diameter of the nerve cell body. Axons have none of the ribosomal machinery responsible for protein synthesis, so all neuronal proteins and peptides must be manufactured near the nucleus and carried out to the periphery. This distribution involves at least two distinct mechanisms, fast axonal transport, moving at almost 500 mm per day, and slow axonal transport, moving only 0.1 to 3 mm per day. It turns out that proteins of the neuronal cytoskeleton, along with many soluble cytosolic proteins, are transported exclusively by the slower process.
To Cheat or Not to Cheat
Authors: Levy Gabor B
Published: March 2018

There has been a recent uproar about falsified data in biomedical research. This occurs with some regularity, and even Congress has been aroused recently with the justification that the perpetrators and the universities where they worked had received public grant monies. The incidents may have been relatively few in numbers, but the fires have been fanned by the media. Less publicized, but perhaps more disturbing is the apparent conflict of interest spread by many new biotechnology companies. Researchers who develop and evaluate their products are frequently given substantial chunks of the companies whose products they are testing.
Site-Specific Cross-sectioning of IC Devices for Failure Analysis by SEM/TEM: Specimen Preparation Challenge and Approach
Authors: Shaapur Farhad
Published: March 2018

Cross-sectioning of microelectronic devices for the purpose of construction or failure analysis by SEM and/or TEM has always been considered a major challenge. The ever increasing complexity and shrinking dimensions of these devices have pushed the art and science of the related specimen preparation beyond their conventional limits. The need for SEM failure analysis of sub-micron elements of a failed device requires the capability of cross-sectioning the sample with a high spatial-resolution within a specific transverse piane. An image of the device structure obtained at sufficiently high magnification from the above specimen generally reveals the defect(s) responsible for the failure. If the imaging resolution and contrast offered by an SEM prove to be inadequate for the above purpose, device structure will be inspected via TEM. Analysis of such device by TEM imposes the additional requirement of back-thinning the above specimen to electron transparency at the site of failure.
How Did You Do that?
Authors: Soeldner Al
Published: March 2018

Methods and results reported to our scientific, technical or law enforcement clients and/or presented in a court of law demand the assurance that all work can be duplicated precisely in every detail. The preparation of technical reports that meet high standards for accuracy and completeness are an ethical responsibility and professional obligation for managers of analytical laboratories.

As the extent or complexity of work increases, more methods and techniques may be employed, producing an array of results. The preparation of reports which accurately describe what was done, how it was done, and what was produced can become a significant challenge. The collection, handling, and analysis of physical evidence can seriously impact the search for the truth, as the O.J. Simpson trial has clearly illustrated.
FIB “Microsurgery” Part 1: A Sample Preparation Tool for the Microscopist
Authors: Laken Dave
Published: March 2018

For sample preparation, e.g. cross-sectioning and thinning, SEM and TEM microscopists routinely use mechanical techniques (e.g., cleaving, slicing, lapping, polishing, and microtoming) and chemical or broad beam ion thinning. Two problems they run into are (1) locating the site of and crosssectioning or thinning at the site of extremely small features at specific locations (site specific samples) and (2) dealing with materials and material systems that are altered or destroyed by mechanical sample preparation (material-specific samples). These material systems may contain multiple components with dramatically different characteristics, such as hardness or chemical reactivity.

Many of these limitations can be overcome by using focused ion beam (FIB) micromachining, often referred to as “FIB microsurgery.” This technique can locate micron and submicron features and use precisely placed cuts to cross section and thin samples.
E.M. Site A.C. Magnetic Field Sources, Surveys and Solutions Part 2: ACMF/EM Antipathy
Authors: Dunnam Curt R
Published: March 2018

A.C. magnetic field (ACMF) sources and their EM interaction mechanisms are discussed in this installment, which continues our July/August series on preventing and resolving site magnetic field problems. This article carries forward the theme of a primer on the basic physical causes and effects of A.C. magnetic fields.with special emphasis on the manner in which such fields may affect site EM instrumentation. Experience has demonstrated that a basic understanding of the various aspects of ACMF sources will often prove helpful in identifying the sources which actually pose a threat to EM site operations.
Biology For Nonbiologists And Support People
Authors: Newberry Sterling P
Published: March 2018

The fact that about half of our readers are not biologists does not mean that they are disinterested in the fascinating current developments in the field of biology any more than the biologist are disinterested in the equally fascinating progress of materials science or physics. Popular press and even trade journals often over simplify or at best give small pieces of information. It is nice when a refereed journal gives a state of the art review. Science Magazine recently gave such a review under the title "Development Frontiers in Biology". As is customary with Science, this issue also contains editorial summaries of many of the contributions in less technically obscure language.