bluuebunny/crossref_metadata_2025 huggingface dataset:
The Scanning Electron Microscope As A Precision Instrument
Authors: Hansen Douglas
Published: March 2018

I began using scanning electron microscopes to solve problems encountered in the fabrication of x-ray diffraction gratings. Since these diffraction gratings consist of very regular lines and spaces, and produce high contrast images from the SEM. my microscopy work often points out problems with the microscope.

One time, for example, I went to the university SEM lab I often use, and was advised that the microscope was down that day due to major field problems. This lab often had problems with stray fields for reasons no one could explain. Usually I was the only one to complain about stray field distortions since they are most obvious when imaging straight lines at high magnification, but on this occasion, the problem was serious and obvious to all.

The microscope had just been serviced and as the lens coils had been replaced, they were expected to be the cause. The service technician was called in and determined that neither the coils nor the microscope electronics were the problem.
Ultra-Low Voltage Scanning Electron Microscopy
Authors: Joy David C , Joy Carolyn S
Published: March 2018

Although the benefits of operating the scanning electron microscope at low beam energies have been evident since the earliest days of the instrument, the successful utilization of the SEM under these conditions has required the development of high brightness field emission electron source, advanced lenses, and clean vacuums. As these technologies became available the level at which imaging became regarded as “low energy” has fallen from 10 keV, first to 5 keV, and more recently to 1 keV. At this energy state of the art, instruments can now provide an excellent balance between resolution - which becomes worse with decreasing energy - and desirable goals such as the minimization of sample charging and the reduction of macroscopic radiation damage - which tend to become more challenging as the energy is increased.
Use of the Digital Signal Processor and Acoustico-Optic Tunable Filters in Ratiometric Confocal Calcium Imaging
Authors: Lohr Christian , Nitschke Roland
Published: March 2018

Since the development of ratiometric fluorescent calcium indicators like Fura-2 and lndo-1 in the mid-eighties, calcium imaging has become a major approach to studying life cell physiology. The ability to calibrate the spectral properties of the dye as a function of the calcium concentration led to measurements of nearly absolute intracellular calcium concentrations in a large variety of preparations. However, the use of ratiometric calcium indicators in confocal calcium imaging is limited, since the dyes are excited by UV light while the lasers of most confocal microscopes provide visible light only. In addition, high energy UV light may cause rapid dye bleaching and photodamage. Thus it appears advantageous to reduce the illumination of the preparation to the minimum possible minimum. The most frequently used dual-excitation dye Fura-2 requires rapidly alternating excitation at 340 ran and 380 nm, respectively, to permit ratiometric calcium measurements with a maximal efficacy.
Care and Use of Microwave Oven for Diagnostic Pathology
Authors: Hayat MA
Published: March 2018

It is well known that biopsy, surgical and postmortem tissues fixed in formaiin and embedded in paraffin require antigen retrieval for diagnostic pathology. Various methods, including heating, enzymatic digestion, ultrasonication, and detergents, are in use for achieving antigen retrieval. A combination of these methods is also employed. However, the most effective methodology for antigen retrieval in a wide variety of tissues involves heating at high temperature using a microwave oven, an autoclave, a pressure cooker, or a hot plate. Among these treatments, heating the tissue sections (4 urn thick) in 0.01 M sodium citrate buffer (pH 6.0) in a microwave oven is the most widely used technique for antigen retrieval. To obtain efficient and reproducible antigen retrieval, the microwave oven must be used carefully and optimally. The following steps are recommended to achieve these goals (Hayat, 2000 a, b).

The causes of most hazards encountered in using a microwave oven are straight forward and can be avoided by taking necessary precautions. Higher power settings and longer durations of heating than optimal for a given study should be avoided. Because overheating is not uncommon, the time setting should be checked.
Quantification of Contaminant Removal by Evactron Cleaning Using Quartz Crystal Thickness Monitors
Authors: Morgan Christopher G , Gleason Mark M , Vane Ronald
Published: March 2018

Hydrocarbon (HC) contamination is a persistent problem for users of electron microscopes (EMs), often leading to image distortion and interference with nanoprobing. The Evactron De-Contaminator (D-C) has been available for HC contamination removal in EMs since 1999. The Evactron D-C uses low power radio frequency (RF) generated plasma in order to produce oxygen radicals that clean the EM. The Oxygen Radical Source (ORS) is attached to the EM chamber, and a controlled leak of oxygen containing gas such as room air is passed through the plasma in order to produce oxygen radicals. The oxygen radicals chemically react with the HCs to form volatile oxidation products such as H2O, CO and CO2. These volatile compounds are pumped out of the EM chamber.
Specimen Preparation for Condoms
Authors: Fang Gan Phay
Published: March 2018

Specimen preparation techniques for Scanning Electron Microscope (SEM) imaging of condoms as reported by Rosenzweig et al revealed a variety of artifacts. The artifacts were classified as ridging, cracking and melting. The purpose of this article is to introduce a simple specimen preparation technique for condoms to be evaluated via SEM without any surface artifacts. This technique involves the use of two chrome washers to sandwich the condom. The sandwiched condom specimen is then subjected to coating before mounting on an aluminium stub. The execution of this technique requires patience and practice so as not to damage the condom. The method may be applied to any similar polymer material.
HMDS and Specimen Drying for SEM:
Authors: Oshel Philip
Published: March 2018

Hexamethyltiisilizane (HMDS) is an excellent method of chemical drying of hydrated specimens. There are several variables involved in its use, the most easily controlled being the number of transitional steps from 100% eihanol (EtOH) to 100% HMDS and the drying temperature.

Fixation and dehydration are the same for both HMDS and CPD. Once thespecimenisinthefinal 100% ethanol, it must then be transferred to 100% HMDS through a graded series of ethanol-HMDS mixtures.
Establishing the Initial Embryonic Axis
Authors: Carmichael Stephen W , Schoenwolf Gary C
Published: March 2018

In the mammalian embryo, the first axis to appear is at the time of the fifth cell division when the inner cell mass (ICM) becomes visible. The localization of the ICM on one side of a cavity formed within the cluster of dividing cells marks the embryonic-abembryonic (E-Ab) axis. This name derives from the fact the most of the embryo will develop from the ICM, whereas other tissues (the placenta, etc.) will develop from the other cells. There has been a long-standing controversy as to what determines the mammalian E-Ab axis; is the information inherently in the zygote, or is it determined after several cell divisions? In an elegant series of studies whereby dividing cells were labeled using new molecular genetic tools and then carefully followed during development, Yoko Kurotaki, Kohei Hatta, Kazuki Nakao, Yo-ichi Nabeshima, and Toshihiko Fujimori have provided an answer in a mouse model.
Applications of the Helium Ion Microscope
Authors: Scipioni Larry , Stern Lewis , Notte John
Published: March 2018

The need for more precise image information of samples coming from fields such as materials analysis, semiconductor processing, and life sciences have pushed the boundaries of charged particle microscopy. A key limitation for the microscope maker in rising to these challenges lies in the relative technical maturity of source technology. Very few changes in sources have occurred in the last generations of tools available to the microscopist, while extensive efforts have been put into reducing aberrations that blur the probe—with their concomitant complexity and cost. Such efforts, representing incremental extensions of these technologies, cannot on their own address many of the emerging needs in nanotechnology. In addition, there are many challenges in the imaging of materials such as polymers and biological specimens that cannot be solved through resolution improvements but rather require different beam sample interaction dynamics. The helium ion microscope (HIM) is a breakthrough technology suited to such challenges.
TEM of Bacteriophages Found in Marine Sources
Authors: Fejeran Adella , Polanco Jesus , Lander Gabriel , Ajero Teddy , Carragher Bridget , Potter Clinton S
Published: March 2018

We describe here a project to illustrate the diversity and abundance of marine bacteriophages undertaken by two high school students participating in The Scripps Research Institute's High School Student Research Education Program. The students were interns in the Automated Molecular Imaging group over the summer of 2007, during which time they acquired high magnification transmission electron microscopy images of bacteriophage filtered from samples collected from nearby marine waters. The basic protocols for sample collection, grid preparation, and electron microscopy imaging are described in this manuscript along with some of the images of the bacteriophages.
Table Top SEM Utilization in a High School Nanotechnology Course
Authors: Leonard DN
Published: March 2018

A Duke University Talent Identification Program (TIP) nanotechnology course curriculum integrated a Hitachi TM-1000 table top scanning electron microscope (SEM) into the classroom to excite and educate gifted and talented high school students interested in this emerging field of research. Students learned about synthesis, characterization and applications of nanotechnologies to encourage them to begin thinking about why and how properties of matter change at the nanoscale. The syllabus was created to introduce fundamental concepts like introductory quantum mechanics, atomic bonding, allotropes of carbon and applications including nanomedicine, nanoelectronics, nano-textiles, bionanotechnology and nanometals. The classroom environment allowed students to take intellectual risks and the course content was presented through a variety of methods to utilize the Kolb learning model and encompass intellectual, personal, social and practical learning methods. The teaching approaches employed traditional principle based lectures, but also included guest speakers, experiential learning activities and both project or problem based learning laboratories.
Down the Resolution Road: Freeze-Fracture Revisited?
Authors: Carmichael Stephen W
Published: March 2018

It must have seemed rather fantastic back in the fifties, when Russell Steere froze chunks of plant viruses (tobacco mosaic virus, tobacco nngspot virus, and squash mosaic virus) in drops of water, planed them freehand with a scalpel blade, made a replica of the surface, and examined the replica in a transmission electron microscope. But that was the birth of freeze-fracture and freeze-etch methodology that yielded enormous amounts of information about the morphology of membranes.
Near-Field Plasmon-Resonance Scanning Microscopy
Authors: Schultz Sheldon
Published: March 2018

In the past few years the field of near-field scanning optical microscopy (NSOM) has developed rapidly with applications spanning all the physical sciences. A key goal of this form of microscopy is to obtain resolution at levels well beyond those possible with the usual far-field optics. In contrast to far-field optics, which is bounded by the well known limits imposed by diffraction, near-field optics has no “in principle” fundamental lower limit in lateral size, at least down to atomic dimensions, although in practice, signal-to-noise considerations may restrict the application of NSOM to a few nanometers.
Poor Man's Faraday Cup
Authors: Walck Scott D
Published: March 2018

Frequently, the need arises for the measurement of the beam current in an electron microscope. For good quantitative analysis with either energy dispersive or wavelength dispersive spectrometers, the beam current is essential. The value of the beam current is used in quantitative microanalysis programs to equilibrate the production of X-ray generation between an unknown sample and a known calibration sample, i.e., a standard. Measurement of the beam current over time can also be quite helpful in determining problems with instrument stability. The following is a description of two very inexpensive methods for making a Faraday cup for measuring beam current in an SEM. It assumes that the microscope has a specimen current meter.
Environmental SEMs: A New Way to Look at Samples
Authors: Chernoff Don , Mujallid Mohammad Salim
Published: March 2018

A new class of SEM has evolved over the past few years which provides some startling capabilities never before available to electron microscopists. These instruments, typically referred to as environmental SEMs or variable pressure SEMs. have opened up a host of new applications that are difficult or impossible with a standard SEM. Many of the constraints of sample preparation and handling that exist with a conventional SEM do not apply to environmental SEMs.

An environmental SEM functions like a conventional SEM except that you can introduce air or any other gas into the chamber and raise the chamber pressure above the normal high vacuum range of 10-5 or 10-6 Torr. Inmost instruments the vacuum can be raised to as much as 1 Torr. This represents a 6 order of magnitude increase in chamber pressure. Environmental SEMs can achieve this high chamber pressure without damage to the electron source by using differential pumping apertures in the column.
New Light On An Old Problem
Authors: Revel Jean-Paul
Published: March 2018

Like many other people I find myself not having the time to do all the things that I would like to do in a day. I have always wished I could emulate the young lady in Prof. Arthur Bullers (1874-1944) limerick which was published in the December 19,1933 issue of that reputed journal, Punch:

“There was a young lady named Bright Whose speed was faster than light. She set out one day, In a relative way, And returned home the previous night.”

Well, up to now I have not succeeded in my attempts to gain time in this way, but there is hope, there is hope as I will try to make clear in a minute.

First of course, as we all know, the speed of light is finite. This was first demonstrated by Roemer in 1676, He measured the interval between successive eclipses of the intermost satellite of Jupiter (that would be lo, with its sulfur spewing volcanoes), at a time when Jupiter was close to Earth.
Are We Reduced To Using Scraps Of Cut Film?
Authors: Newberry Sterling
Published: March 2018

Kent Christensen documents the values of glass photographic plates1 and also their demise. As a former user of glass plates for microscopy, radiography, autoradiographyandspectroscopy, I sympathize with Kent. Today there are substitute sheet and or roll films for most of the glass plate applications. For example, [ have found Kodak's "Trnax" films as sensitive as lantern plates for soft X-rays and nearly as good for resolution. Tmax is also a good general purpose emulsion for the laboratory, with the possibility of reversal development for slides and availability in a range of formats including 120 and four by five. Perhaps we should recognize the passing of the glass plate as part of current times and inscribe "RIP" over our hallowed collection of glass negatives. After all, many predict that electronic photography will eventually replace all forms of chemical photography.
Leonardo DaVinci: The First Photographer?
Authors: Compton Bob
Published: March 2018

Some 350 years before the invention of photography, Leonardo DaVinci may very well have produced the first photograph - the Shroud of Turin. This extraordinary hypothesis attracted shroud experts Lynn Picknett and Clive Prince, and their efforts to prove or disprove this theory resulted in their recent book Turin Shroud. During their shroud investigations, the authors delved deeply into historical lore, piecing together diverse facts and opinions including those of such figures as the Knights of Templar, alchemists, secret societies, and even Pope innocent VIII. The authors provided convincing evidence that the shroud could have been produced using photograph i c -like techniques that were within the identified capabilities of DaVinci. Most importantly, the authors were able to recreate shroud "look-alike" images with materials and techniques believed to be available to, or devised by, Leonardo DaVinci in the creation of the Turin Shroud.
Automatic Particle Picking From Electron Micrographs
Authors: Ramani Lata K , Penczek P , Frank J
Published: March 2018

The present-day interactive manual selection of biological molecules from digitized micrographs for single particle averaging and reconstruction requires substantial effort and time. Thus a computer algorithm capable of recognition of structural content and selection of particles would be desirable. A few approaches have been proposed in the past. The method by Frank and Wagenknecht is based on the principle of correlation search. Van Heel's method is based on the computation of the local variance over a small area around each point of the image field. The method by Harauz and Fong- Lochovsky is based on edge-detection.
The Annular Cutting of Important Samples for Microscopy
Authors: Hazeldine T A
Published: March 2018

A precision sectioning method is described in which the diamond blade used is specifically mounted at high tension, with the sample being fed into the blade at its inner annulus. The sawing action which results is characterized by low kerf losses, the possibility for thin slices, good surface finish, high straightness, high reproducibility and low damage. Applications which benefit from the method are mentioned, namely in the sample preparation of semiconductor, geological, composite, hard tissue and polymeric samples, as well as most non-biological samples for many areas of microscopy.
An Improved Clamp for Gluing TEM Cross Section Samples
Authors: Li Hao , Salamanca-Riba L
Published: March 2018

It is crucial to get a thin glue line when making TEM cross section samples, so normally a clamp is used to press the samples together during curing. Several types of clamps are available commercially, however almost all of them have a big disadvantage: the pressure cannot be adjusted. Basically there are two types of clamps. Type 1 is a small vise that uses a screw to press the samples together. There are two problems associated with type 1. The first one is that usually the viscosity of the glue decreases during the initial stage of curing, so even if you had tightened the screw hard, the sample could still get loose because the glue becomes thinner as its viscosity reduces. To get a thin glue line with this type of clamp, one has to keep retightening trje screw when the clamp and sample is being heated.
"Chip Wars" Heat Up On The Digital Imaging Front
Authors: Chiovetti Bob
Published: March 2018

Although the Charge-Coupled Device (CCD) imaging chip is the standard in today's video and digital cameras, things may change during the coming year. The CCD chip is being challenged by a competing device, the CMOS ("C-moss") chip.

CMOS is the most widely used type of integrated circuit for memory and digital processing, virtually everything in computers is CMOS based. The economies of scale and production of CMOS devices are the main reasons why computer prices have continued to drop during the past few years. If a device or an instrument has a microprocessor in it, chances are it includes CMOS technology..
False Engagements in AFM
Authors: Dandavate Chetan
Published: March 2018

In scanning microscopes, like the Atomic Force Microscope (AFM), used in contact mode, scanning begins with engaging the tip with the sample at some contact force, which can be adjusted by the setpoint* (this is common to Digital Instruments' AFMs). It may differ for other brands. For a system that detects the motion of the cantilever with a laser beam, the setpoint basically gives an idea of the voltage difference between the top and bottom photo detectors, When the tip comes into contact, the feedback circuit adjusts the tip deflection according to the required contact force, This is the method commonly followed for the constant deflection method.
How to Slam a Cell
Authors: Carmichael Stephen W
Published: March 2018

Many important discoveries in cell biology have been made by introducing specific compounds into a certain cell and observing the effect. Several methods have been used for the introduction of the compounds. For example, permeabilizing the cell by electroporation (an electric shock that has been demonstrated to poke holes in the plasma membrane), the use of biologic molecules (such as streptolysin 0) to create channels in the plasma membrane, or detergents to dissolve hoies in the plasma membrane. Several laboratories have shown these methods to be effective, but one questions the physiologic state of a holey cell. Liposomes or similar vehicles can be packed with compounds and fused with the cells of interest, but this method of introduction has drawbacks as well.
Web Site Development at a Museum Microscopy Laboratory
Authors: Reddy David P , Klaus Angela V , Recker Renée , Barnett William K
Published: March 2018

The Interdepartmental Laboratories (IDL) is the core microscopy and scientific visualization research facility for the American Museum of Natural History (AMNH), Its purpose is to operate and maintain facilities that have broad application within the Museum and would be either too costly for the individual research departments to maintain or which would be underused in a typical department setting, The IDL currently maintains two state-of-the-art analytical/imaging microscopes, as well as resources for visualization, webaccessible databases, and networked image scanning, archiving, and printing. The IDL is overseen by Bill Barnett, the IDL Director, and staffed by Angela Klaus, the Laboratory Manager, and David Reddy, the Scientific Visualization and Informatics Manager.
Scientist Uncovers Chipmakers' Micro-Art
Authors: Yeager Melanie
Published: March 2018

Tallahassee, Fla. - Dan Zuras admits he never thought he'd be alive when a scientist discovered the microscopic Road Runner image he engraved on a computer chip 16 years ago.

But then again, at the time, who knew the minute circuitry of microprocessors would grace the pages of wall calendars in the 1990s?

Wee pictures of everything from animals to license plates have become the signatures of chip creators, But knowledge of this practive generally stayed within industry circles - until Florida State University researcher Michael Davidson discovered the imprints left by engineers under his highpower microscope.
Imaging with the Photon Scanning-Tunneling Microscope
Authors: Ferrell Thomas L , Meriaudeau Fabrice , Passian Ali , Goudonnet Jean-Pierre , Wig Andrew
Published: March 2018

The use of traditional optics in microscopy has a well-known resolution barrier first presented by Lord Rayleigh. This is the "Rayleigh diffraction limit." In the usual textbook example, the overlapping diffraction rings from two small objects are set so that the central maximum of one pattern falls on the first minimum of the second, The barrier limits the resolution of conventional microscopes to a significant fraction of the wavelength of light.

In the past decade two methods were discovered for surpassing the Rayleigh diffraction barrier. The first was actually an independent rediscovery by D. Pohl er al. of a concept originally proposed by Synge (in a 1928 paper reviewed by Albert Einstein),
Imaging Mechanisms in Dynamic Force Microscopy of Polymers
Authors: Haugstad Greg D
Published: March 2018

Applications of scanning force microscopy (SFM) in polymer studies have flourished in this decade, reflecting (a) sensitivity to both structure and properties on the nanometer scale, and (b) ease of operation in ambient environments without sample pretreatment. One drawback in SFM of soft materials has been damage incurred during the imaging process. The problem was alleviated by the development of dynamic force microscopy (DFM) in which the probe spends little or no time in contact with the polymer surface and shear forces are minimized. This mode of operation has been dubbed "tapping", "intermittent contact", "non-contact", "near-contact", etc. As studies proliferated, it became apparent that different researchers were using different terms to refer to the same apparent imaging mechanism, or the same term to refer to different imaging mechanisms.
Integrity of Scientific Imagery: Photoshop v.4 versus v.5
Authors: Shaffer Michael
Published: March 2018

Having installed Photoshop 5 after using version 4 for some time, I think that all scientists who believe that the integrity of their imagery is important, understand what Photoshop 5 brings with it: the issue of "color space" or color profiles". Whereas users could rely on the integrity of their image being retained with Photoshop 4, this changes with version 5, and in some cases rather severely. For example, a image bitmap which might represent elemental spatial distribution data should be considered to have a gamma of unity. Photoshop 4 would represent this data for editing via the display monitor's gamma compensation only. That is, the integrity of the pixel values would remain and visual compensation happens between data and display. Photoshop 5, on the other hand, will modify pixel values in accordance with either a desired "working" color space or an anticipated "target" color space.
Method for Analyzing Nitrogen in Titanium Alloys
Authors: Mager Mary
Published: March 2018

Careful analysis of the composition of the titanium alloys is a very critical part of the overall quality control of all components in modern jet aircraft engines. The engine manufacturing industry is seriously striving for a zero defect rate, which is a very difficult goal indeed. This control is made more difficult by the very reactive nature of titanium when it is heated to its melting point. Titanium reacts with the nitrogen and oxygen in the air to form brittle refractory compounds, so it must be melted and refined in a vacuum. Once these refractories are formed they are very difficult to find or remove and they form the basis for brittle zones in the alloy that can be the initiation site for cracks under the high stress loads found in a jet engine. The presence of nitrogen, in particular, causes a defect called a "hard-aipha", which is an area of nitrogen enrichment containing three to eight percent nitrogen and having a hardness three times that of the alloy.
Microanalysis Made Easy: Attenuated Total Reflectance (ATR)
Authors: Tague Thomas
Published: March 2018

Reflection microscopy techniques are typically the easiest to employ for routine sample analysis, as they require little or no sample preparation. Included in these methods are reflection- absorption spectroscopy (RAS), which emulates transmission spectroscopy, diffuse reflection infrared spectroscopy (DRIFT), specular or external reflectance, and attenuated total reflectance (ATR). For RAS, DRIFT, and specular reflection, the nature of the resultant spectra is determined by the nature of the sample. These techniques will be discussed in future articles. ATR is primarily a surface technique which provides a high quality absorbance-like infrared spectrum and can be used to readily analyze almost any liquid or solid sample.
Evanescent-Wave Microscopy: Peeking just Under the Surface of the Cell
Authors: Carmichael Stephen W
Published: March 2018

There are many techniques available that enable us to know what is happening at the surface of a living cell. These techniques have allowed us to characterize many aspects of the process of exocytosis, the fnal cellular event in secretion. Patch clamping has given us quantitative measurements of the capacitance changes as the membrane of the secretory vesicle is added to the surface of the cell during exocytosis, and the change in the opposite direction as membrane is retrieved back into the cell during endocytosis. Tiny probes have measured electrochemical changes just outside the surface of the cell as reactive molecules are released into their surroundings. Differential interference contrast microscopy has given us high resolution pictures of the cell surface during exocytosis; real-time images are suggestive of bubbles breaking the surface of a boiling pot of water. However, exocytosis is known to be proceeded by an ordered series of events that occur below the surface of the cell.
Clinical Laboratory Reagents: The Regulatory Hurdle
Authors: Takes Peter A
Published: March 2018

Today's clinical laboratory has a diversity of reagents and protocols from which to choose: a variety of clinical chemistry reagents, antibodies, and molecular probes, among others. These materials facilitate serum and urine analysis, histology, hematology, cytology, and a host of additional sensitive and specific assays

Regardless of the application, labs may see an array of labeling statements indicating a reagent's general use: "For Laboratory Use Only" [LUO]; "For Research Use Only" [RUO]; "For Investigational Use Only" [IUO]; "For In Vitro Diagnostic Use" [IVD]; and "Analyte Specific Reagent" [ASR]. These preparations are often employed without realizing the course manufacturer's must follow in order to provide reagents, and the reasons for these designations.
Avoiding Etching of Silver When Using Silver Staining With OsO4 Fixation
Authors: Powell Rick
Published: March 2018

Post-fixing with osmium tetroxide before silver-staining sections causes problems because the OsCU can etch the deposited silver. However, it is not a good idea to perform silver enhancement after osmium tetroxide treatment because the deposited osmium can also act as a nucleating site for silver deposition, and the osmicated regions of the sample will be silver enhanced. If gold-toning is used after OsO4 post-fixation, the OSO4 can also nucleate gold particles. OsO4 should always come after silver enhancement.
Confocal Laser Scanning Microscopy By Remote Access
Authors: Youngblom JH , Wilkinson J , Youngblom JJ
Published: March 2018

In recent years there have been a growing number of facilities interested in developing remote access capabilities to a variety of microscopy systems. While certain types of microscopes, such as electron microscopes and scanning probe microscopes have been well established for telepresence microscopy, no one has yet reported on the development of similar capabilities for the confocal microscope.

At California State University, home to the CSUPERB (California State University Program for Education and Research in Biotechnology) Confocal Microscope Core Facility, we have established a remote access confocal laser scanning microscope facility that allows users with virtually any type of computer platform to connect to our system.
Combining FIB and Automated Microcleaving Provides Fast, Accurate Cross Sections
Authors: Teshima Janet
Published: March 2018

A large part of the preparation of semiconductor samples for SEM and TEM observations involves the creation of cross sections to expose subsurface defects and three-dimensional structure. A powerful new combination of FIB (FEI Company, Hillsboro, Oregon, http://www.feic.com ) with automated microcleaving technology (SELA, Santa Clara, California, http://www. sela.com ) now offers a comprehensive solution for fast, easy and accurate sample preparation.
A Personal View of the History of Twin-jet Electropolisher
Authors: Langford George
Published: March 2018

Way back in 1966, when I first started my industrial career at U.S. Steel's Edgar C, Bain Laboratory for Fundamental Research (which is what it was called before it became a grease spot in Corporate America) Gene Fischione and Dick Glenn were engaged in a "moon race" of sorts to bring out some of the earliest electrolytic jet polishers. Remy Schoone helped Gene build his model; and Bob Sober helped Dick make the competition, I haven't used either one of these fine instruments in nearly thirty years, so the only connection is historical and the good feelings I have about the four nice guys who made them.
Color Image Analysis In Optical Microscopy
Authors: Laroche Sylvain
Published: March 2018

Most of the applications in microscopic image analysis are still salved by a heuristic method that focuses on the specificity of each problem. This is particularly true for applications involving color images. Because of this, the design of robust algorithms has remained time consuming and is usually performed by an image analysis expert with many years of experience. How then can the knowledge of the expert be transferred to the less specialized microscopist? How can the specificity of a typical application be related to general color image analysis tools?

Only a general approach can work towards decreasing the heuristic aspect of the design phase and help the common user perform image analysis without the assistance of an expert.
Does the Scanning Electron Microscope Have an Objective Lens?
Authors: Roth Ivan L
Published: March 2018

No, Virginia, there is no objective lens in the Scanning Electron Microscope.

There is much confusion about the lenses in a scanning electron microscope (SEM). All of the lenses in a SEM are condenser lenses. The fact that some scanning electron microscope manufacturers have labelled the controls for the final condenser “objective lens” is misleading and this may have contributed to the confusion.

To get some perspective on this matter, observe your compound light microscope. Starting with the light source, the first lens encountered is the condenser lens (the lens that handles the light before it interacts with the specimen). Next the light interacts with the specimen on a microscope slide. Then the light enters the objective lens (the first lens the light enters after interacting with the specimen) and finally the light travels through the ocular lens and then it enters your eye.
The Bright Future of Digital Imaging in Scanning Electron Microscopy
Authors: Postek MT , Vladar AE
Published: March 2018

One of the major advancements applied to scanning electron microscopy (SEM) during the past 10 years has been the development and application of digital imaging technology. Advancements in technology, notably the availability of less expensive, high-density memory chips and the development of high speed analog-to-digital converters, mass storage and high performance central processing units have fostered this revolution. Today, most modern SEM instruments have digital electronics as a standard feature. These instruments, generally have 8 bit or 256 gray levels with, at least, 512 X 512 pixel density operating at TV rate. In addition, current slow-scan commercial frame-grabber cards, directly applicable to the SEM, can have upwards of 12-14 bit lateral resolution permitting image acquisition at 4096 X 4096 resolution or greater.
Automated Functions in Electron Microscopy
Authors: Tivol Bill
Published: March 2018

The newest generation of computer-controlled electron microscopes incorporates the ability to perform adjustments to microscopy conditions by comparing pairs of images and altering the conditions accordingly. Automation of electron microscope adjustments offers the advantages of accuracy, precision, efficiency, the ability to incorporate the adjustments into other automated procedures, and, for radiation-sensitive specimens, minimal exposure to the beam.

At present, automated functions include determination of eucentric height, focus, astigmatism, orientation and location of the stage tilt axis, centering of an image feature, and rotation center alignment. It is possible to automate other functions, so this list may be incomplete. In general, these functions are accomplished by induced image shifts, and, in many cases, the automated functions are completely analogous to the corresponding manual ones.
Neutralization of Osmium Tetroxide in Case of Accidental Spillage and for Disposal
Authors: Cooper K
Published: March 2018

In October 1979, a technician in the electron microscopy laboratory of one of the teaching hospitals in Toronto spilled a bottle containing approximately 500 ml of 2% osmium tetroxide. He asked for help, and four other technicians were involved in the cleanup. They all were exposed to osmium tetroxide vapours for long enough to show signs of acute intoxication. They developed redness and swelling of the conjunctiva, impaired vision, chest pains, breathing difficulties and skin irritation and were taken into Emergency Care at the hospital. The occular symptoms disappeared after two days, but the chest pains and breathing difficulty persisted for approximately one week.

This accident could have had more serious consequences. It has been reported that exposure to osrruum vapour could lead to blindness and serious respiratory trouble. At McMaster University Medical Centre, the safety committee gives precise procedures to be followed in case of accidents with dangerous chemicals. All the occupants of the laboratory have to leave immediately and phone the safety and security team.
Low-Cost Hot Stage For Crystal Studies
Authors: Silk Ely
Published: March 2018

I required a hot stage to do some work with iiquid crystals. Hot stages on the market are very expensive. I decided to try using electro-conductive glass, This is the NESA glass used by automotive manufacturers in electrically operated defrosting windows, A local glazier ordered some of the glass for me in 8 x 8 inch squares, i had the squares cut and edge polished into 2 x 2 inch pieces by a filter manufacturer. One sheet of 8 x 8 inch glass cost me about $15.00. Cut down, I got nine 2 x 2 inch pieces suitable for my experiments at an additional cost of $3.00 per cut piece.

A piece of 2 x 2 inch electro-conductive glass is prepared with two thin copper strips epoxied to the outer margins. One needs a conductive epoxy, and i used a silver epoxy (40-3900 resin and catalyst) obtained from Epoxies, Etc. of Greenville, Rl.
Technical Excellence In Muscle Biopsy Preparation
Authors: Lincoln Clint
Published: March 2018

More than a quarter of a century after the publication of Dubowitz and Brooke's classic Muscle Biopsy; A Modern Approach in 1973, there seems to be a lingering confusion regarding the proper technique for freezing muscle biopsies, and whether or not enzyme activity will be preserved. I have worked with muscle from humans, dogs, and rodents in my quarter of a century in histology, and would like to address the proper technical procedure to follow to insure high quality sections.

The first step is to acquire tissue immediately after excision, as any delay may alter the morphologic and enzymatic characteristics. If there is a slight delay between excision and freezing, keep the tissue covered with a gauze moistened (not soaked) in normal saline.
Detection of Ophiostoma Piceae in Radiata Pine using Immunofluorescence Labeling and Confocal Laser Scanning Microscopy
Authors: Xiao Ying , Kreber Bernhard , Breuil Colette
Published: March 2018

The use of fluorescence microscopy to investigate fungal growth in wood often causes interference due to the strong autofluorescence of wood lignin, unless fluorescent probes which specifically react to fungal hyphae, are used. Techniques to enable differentiation of hyphae from wood have been recently reported (Singh et al., 1997; Xiao et al., 1997). The authors demonstrated that while glutaraldehyde can be used to detect fungal native proteins, wheat germ agglutinin (WGA) which reacts with cell wall chitin of hyphae, considerably improved detection of fungi growing in wood.
TEM Sample Preparation for the Semiconductor Industry - Part 2
Authors: Laken Dave
Published: March 2018

In the November issue of this publication, we described how focused ion beam (FIB) microsurgery is used to successfully cross-section and prepare material-specific samples for SEM and TEM analysis. Material specific samples have two or more components possessing different characteristics, such as hardness and chemical etch or sputtering rates. Traditional sample preparation techniques (mechanical grinding and polishing, broad ion beam etching, and chemical etching) alter, delaminate, or destroy these samples.

FIB handles the preparation of these difficult samples well because of its milling geometry and the high current density of the small beam.
Forty Years of X-ray Mapping, from the Beginning to Position-Tagged Spectrometry
Authors: Friel John J
Published: March 2018

The ability of scanning beam x-ray microanaiysis to show the spatial distribution of elements was recognized quite early. At first it was done one element at a time by wavelength dispersive spectroscopy (WDS), but when energy dispersive spectroscopy was developed, that became the technique of choice. Because there have been several significant improvements in the technology, and also because maps are used so universally, I thought a review of the technology from the early days to the latest technology might be interesting. Though modern maps are ail digital, the original analog “dot” maps are used by a few even to this day. Other names for the technique are sometimes used such as “x-ray image”, which is correct but can be confused with radiography. Compositional image has also been used, but the term is broad and includes more than x-ray maps. Consequently, the universally recognized term “maps” will be used.
Staying Alive: Another View
Authors: Blackwood Andrew W
Published: March 2018

Al Soeldner's article in the November issue of this publication entitled “Staying Alive” contains a lot of good, solid advice that all of us who operate service laboratories should take to heart. Whether our laboratories are public or private, his advice on sticking to what we know how to do, understanding how to put the client first in the “service” environment and establish a “user friendly” climate is sound and should be clearly heard by all.

There is, however, one point on which I do not agree with Al, and that is the scope of work which is appropriate for various laboratories. While he does discuss the possible problem of “agency policy” which may conflict with offering services to a broader user base, he might not emphasis that the problem created by the agency policy (if it exists) is probably based on a solid understanding of the legal climate in which we all operate.
Some Reflections on How Much Information is there on a Piece of Film, on How Film Compares with CCD Cameras and what Features a Scanner would need to Digitize TEM Negatives
Authors: Eades Alwyn
Published: March 2018

The world of electron microscopy is in a period of transition from acquiring images on film to acquiring images digitally, using CCD cameras, for example. It would be useful to know how much information there is on a piece of film, in order to know how film compares with digital methods and to be able to make good judgements on the optimum moment to change from one technology to the other.

This is an attempt to use simple arguments to estimate just how much information there is in an image exposed on film in the transmission electron microscope. The main reason for addressing this issue is that, while many people are affected by it, there seems to be little agreement on the answer.
Preventing Nuclear Artifact in Hematologic Specimens
Authors: Santoianni Robert
Published: March 2018

The bubbled, popcorn or moth-eaten appearance of nuclei hampered accurate microscopic evaluation of bone marrow and lymph node biopsies. This artifact was also noticed in skin biopsies, but had little bearing on diagnosis. All aspects of specimen handling processing and staining were scrutinized and improved morphological detail was attained only after blocks were recut and allowed to dry completely before staining.
A Note On Paraffin Waxes, Their Crystals, And Microtoming
Authors: Allison Russ
Published: March 2018

Paraffin wax is a mixture of (virtually) straight chain hydrocarbons. Note the word “mixture”. Unless one goes to the enormous lengths of purifying or searching for a fine chemical supplier, the wax will always be a mixture. I used a “pure” wax once as a standard for gas chromatographic studies on paraffin waxes. There is a relationship between hydrocarbon chain length and melting point, but as the waxes are always mixtures, melting points are never exact, either in the compounding or the measuring.
The Digital Precision Imaging Laboratory Part I: The New Tools of Differential Contrast Imaging
Authors: Peters Klaus-Ruediger
Published: March 2018

In recent years, many developments in imaging instrumentation and support technologies have put in question the conventional way of working with images. Conversion from analog to digital imaging is pursued at all levels of microscopy driven by the benefits of new forthcoming digital precision imaging technologies for visualization and quantification of the image information. These developments will revolutionize microscopy by extending the information retrieval from the level of the full-frame image to the level of individual pixels.
An Effective, Cost-Free Holder/Desiccator for Storage of SEM Stubs
Authors: Walker Glenn , Hartenburg Jerry , Edwards Chris
Published: March 2018

Two of the aggravations of effectively managing an EM unit are cost containment and effective storage of large numbers of specimens. For the past several years we have enjoyed the benefits of a stub-storage box (for pin-type stubs) available to microscopists without cost. These boxes, which held micro-pipette tips, are regularly discarded by molecular biology and biochemistry labs, in fact, since colleagues have recognized that we use their spent plastic boxes, we have been inundated with boxes originally slated for recycling. While several types of these boxes are available, most measure approximately twelve cm by eight cm and have a plastic platform with ninety-six holes. The boxes hold eight one-inch stubs and six half-inch stubs or thirty-two half-inch stubs.
Computer Control of Transmission Electron Microscopes: Possibilities, Concepts and Present Limitations
Authors: Völki E , Allard LF , Dodson TA , Nolan TA
Published: March 2018

The electron microscope laboratory at the High Temperature Materials Laboratory in Oak Ridge National Laboratory runs essentially film free. This is possible due to the use of TV-rate and slow-scan CCD cameras together with fast desktop computers connected through Ethernet to network servers for image storage; and a variety of hard copy output devices. In our experience, the functionality of a film-free laboratory goes beyond the simple replacement of film material with some other storage media. For example, the time and effort to produce a final hardcopy image has been reduced effectively from several hours to several minutes. At the same time, data accuracy has increased due to the high linearity of the CCD cameras and data safety is improved due to automated nightly backups.