In North America, one could very easily get a distorted view of the rest of the world when it comes to internet access. in the USA and Canada, one can stay connected continually, without regard to cost. And the connections tend to be fast and convenient.

But this is not the case in most of the rest of the world. While there are some notable exceptions, Australia and Israel for example, many in the international microscopy and microanalysis community have to struggle with connections that are either very slow, or very expensive, or both, in fact, in many parts of the world, internet content is routinely not with the benefit of graphics. This is really a great disadvantage since, in many instances, the real important information is contained within the graphics. Even in the USA and Canada, because of firewall considerations or other concerns, a surprisingly large number of end users do not have internet access at their main workstations, and they have to suffer the inconvenience of using some kind of shared resource, either “down the hall” or worse yet, in another building.

Ready or not, digital imaging in the microscope lab is here to stay. While I am one of those fogies who insist that digital images are nowhere near as good as photographic prints, I've also bowed to the inevitable, and begun to find ways to assist clients in our multi-user facility with their digital imaging needs. We can acquire digital images from our FESEM, with a CCD camera on our EFTEM, from our light microscope with a CCD, and from a flatbed scanner. Clients use their images for image analysis, transport to others scientists via the Internet or World Wide Web, for reports, slides, overhead transparencies, and publication. Generally, these images need to be manipulated for use, just as one wouid manipulate a photographic print in the darkroom to correct any deficiencies in exposure or area of view.

Although scanning electron microscopes (SEM) have been used to study the polyolefin polymer morphology as it relates to the development and modification of the commercial products, it has seldom been used to study polyolefin microstructures such as spherulite and lamellae morphology. Rather, transmission electron microscopes (TEM) have been used for such morphology studies because they provide the resolution necessary for observation of polymer microstructures. Unfortunately, TEM studies require the microtomesectioning of the buik samples to produce suitable test samples after unloading. In contrast, we have shown that, if suitable sample preparation techniques are employed, the surface morphology of bulk polyolefin samples, such as the thick test pieces and commercial products, can be characterized using the SEM. In this article we introduce our chemical etching technique that is suitable for the investigation of the polyolefin microstructures.

The preparation of histological sections of teeth can be both a rewarding and a frustrating experience. This is primarily due to the varying degrees of mineralization of the enamel, dentin, cementum and surrounding bone and the difficulty in retaining original relationships between the calcified and the soft tissues in the final stained section.

The tooth has a central pulp that is a gelatinous loose connective tissue. Surrounding this is dentin that forms the main bulk of the tooth, is composed chiefly of collagen fibers and is approximately 70% mineralized.

With the advent of Mohs surgery in the dermatology clinics, making sure the margins are clear of any cancer is of the utmost importance to both patient and dermatopathologist. While the patient is still in the surgery suite, immunohistochemstry staining can be done in the laboratory microwave (Pelco microwave with water load cooler, wattage controller and temperature probe). The immunohistochemistry procedure takes only 25-30 minutes as compared to the more conventional methods that take 2 hours or more.

The microwave needs to be checked for hot spots using the Pelco #36140 microwave bulb array. Make sure the area in which you are going to put your slides has no hot spots, indicated by no illuminating bulbs. Using a Sigma Diagnostics #H6644 Humid Chamber, place a paper towel in the bottom of the chamber and fill with 1/4 inch of water. This is in addition to the water loads used to eliminate hot spots.

Project MICRO (Microscopy in Curriculum - Research Outreach) is an initiative by the Microscopy Society of America (MSA) to connect scientists with middle school teachers in an effort to introduce young students to the scientific method. Through a collaboration with the Lawrence Hall of Science (LHS) at the University of California, Berkeley, a teacher's manual was produced as part of the LHS GEMS (Great Explorations in Math and Science) series. This manual, entitled “Microscopic Explorations”, can be used by scientists and middle school teachers alike to prepare a Project MICRO “Festival” to be presented in the classroom. Detailed information concerning Project MICRO in general, and the Microscopic Explorations manual can be obtained from the Project MICRO web page from MSA (http://www.msa.microscopy.com/ProjectMicro/PMHomePage.html).

It has been estimated that more than 90% of all scanning electron microscope (SEM) images ever published have been obtained using secondary electrons (SE) which are defined as those electrons emitted with energies between 0 and 50 eV. The properties of these secondary electrons are therefore of considerable interest and importance. However, although secondary electrons have been intensively studied since their discovery by Starke in 1901, the majority of the work has been aimed at determining the SE yield coefficient and its variation with energy for elements and compounds. The energy spectrum of secondary electrons has received far less attention although it is evident that the form of the spectrum must have an effect on the image contrast observed in the SEM because SE detectors are energy selective devices. The few studies that have been made have mostly concentrated on spectra obtained from clean samples observed under ultra-high vacuum conditions.

The increasing availability of the user-friendly black box can present an increased probability of characterization errors. The uninformed choice (e.g., any SEM will see this) or dependence on one instrument can also lead to erroneous results. Failure to understand the limits and advantages of a particular instrument and bias through assumption or desired result can be equally deceptive.

In the example presented here, the objectives are to determine primary particle size and to identify the impurities in a specimen. We will look at the data produced by several instruments and discuss the ways each technology can support or mislead the analysts.

Images were acquired optically by secondary electron (SE), x-ray dot maps and back scattering electrons (BSE). The elemental analysis techniques used were Energy Dispersive Spectrometry (EDS), Wavelength Dispersive Spectrometry (WDS) and Powder x-ray diffractometry (PXD).

Field emission SEM (FESEM) and optical images are used.

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.

Having seen these effects often enough, and fielded questions on them from fellow AEM users, we'd like to share our speculations about surface charging effects on semiconductor and insulator surfaces. We do not claim the following to be authoritative, but just what we consider a reasonable explanation for some strange phenomena we have observed.

We have witnessed a slow but steady decline in electron microscopy (EM) skills in the biological sciences over the last decade. This decline is illustrated by the continued closures of EM facilities throughout the world. It is, however, difficult to rationalize this decline when the need for these skills is still under a constant demand. Certainly, the introduction of new microscopes has played a part in this. High-resolution confocal light microscopes, two photon imaging and other new technologies are providing impressive amounts of new information on biological systems. Many of these approaches require simple preparation protocols providing information that can be easily interpreted and are thus easily adapted to fast-moving research.

The application of EM techniques is also deceivingly simple. For this reason the field of immunocytochemistry is undergoing an increase in popularity. Laboratories with little or no previous experience in EM are discovering the impressive and convincing results achievable using these high-resolution methods.

The advent of the Internet has allowed the development of remote access capabilities to a growing variety of microscopy systems. The Materials MicroCharacterization Collaboratory, for example, has developed an impressive facility that provides remote access to a number of highly sophisticated microscopy and microanalysis instruments, While certain types of microscopes, such as scanning electron microscopes, transmission electron microscopes, scanning probe microscopes, and others have already been established for telepresence microscopy, no one has yet reported on the development of similar capabilities for the confocal laser scanning microscope.

“I will be getting my first SEM/EDS shortly, and to obtain the required operating permit from my safety group, I need a written procedure for handling LN2. Specifically I need a written procedure for filling the 3 L dewar on the EDS detector from a 50 L dewar mounted on a cart. I plan to make the transfer by using a lab source of LN2 to pressurize the 50 L dewar and have obtained all the valves and fittings required to do this from another SEM lab. I would appreciate copies of the procedure.”

This question recently posed to the Microscopy List Server unleashed a flurry of comments, not only on the safety of various LN2 procedures but on the safety of other materials as well. Also discussed was the necessity of formal LN2 handling procedures.

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.

The programmable array microscope (PAM) is a powerful tool combining the capabilities of nearly all previously described optical sectioning techniques in a single microscope. Not only can the user create optical sections of threedimensional objects, but the PAM's unique adaptive optical strategy allows a user to select the best sectioning method for a particular sample or experimental need. The key to the PAM is a spatial light modulator (SLM). This device, when placed in the image plane of a microscope, can be used to create optical sectioning, generate spatial encoding masks, and/or define regions of interest. The growing family of PAMs includes optical sectioning systems operating in fluorescence4'3'7112 and reflection7'112, as well as spectroscopic imaging systems for fluorescence emission spectroscopy. Perhaps the most common application of this unique family of adaptive optical systems is optical sectioning.

It can be a problem to get suspended (or plated) cells or particles to settle into the apex of a BEEM capsule for embedding, particularly if the cei is/particles can not be embedding in agar or gelatin for some reason. The following simple procedure solves this problem.

Process the suspensions in polypropylene test tubes or microcentrifugation tubes. These can be spun down after each transfer for 5 minutes at 3000 rpm. Once the cells/particles are fixed, en bloc stained, and infiltrated with either Spurr's or LR White resin, I transfer them to BEEM capsules. I do not add additional resin yet. These are placed piggyback in microcentrifuge tubes that have been slit with wire cutters to make them large enough for the BEEM capsules to fit (see following illustration).

Processing cell suspensions or plated cells can be done in polypropylene test tubes or microcentrifuge tubes. These can be spun down after each transfer for 5 minutes at 3000 rpm. Once the cells are fixed, enbloc stained, and infiltrated with either Spurr or LRWhite resin, I transfer them to BEEM capsules. I do not add additional resin yet.

Recent advances in cameras and computers have made it possible to build electron backscattering diffraction (EBSD) cameras which can give crystallographic information from specimens in the scanning electron microscope (SEM) on a routine basis. There are a few hundred such systems world wide and the number is growing fast. In the case of crystalline samples (nearly all applications of SEM outside the biomedical field), it will surely soon be considered essential to fit an SEM with an EBSD system, just as it is now considered essential to have the SEM equipped with an energy-dispersive x-ray spectroscopy (EDS) system. There are at feast four commercial manufacturers of EBSD systems.

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.

All insects have an exoskeleton made of chitin, which is a protein that is hard and impervious to moisture. To enable processing reagents to more effectively enter the body cavity, a small slit in the abdomen can be made. For very small insects, such as the fruit fly, Drosophila, micro dissecting tools can be made from commonly found items such as insulated electrical wire, double edged razor blades and wood applicator sticks.