Whereas too much of a good thing can be bad, too little of a good tiling can be good. In this case, the accidental dilution of X-rhodamine tubulin injected into living cells resulted in a heterogeneous labeling of micro tubules, rather than visualization of continuous structures. This heterogeneous labeling rendered a speckled image, hence the term fluorescent speckle microscopy (FSM) was introduced. It turns out that FSM yields particularly useful information on dynamic events within living cells, for example the assembly and disassembly of microtubules.

There are two recent reviews of FSM by Clare Waterman-Storer and Gaudenz Danuser, one emphasizing the biologic applications of the technique, the other emphasizing the quantitative aspects. For their purposes, they defined a “speckle” as a diffraction-limited region of the image that is significantly brighter than its immediate environment. It can be calculated from the point-spread function (which is determined by the numerical aperture of the lens) that optimally a diffraction-limited region of about 250 nm can be imaged.

The small unassuming nematode, Caenorhabditis elegans is only one millimeter long and lives in the soil munching on bacteria. While many nematode (roundworm) species are parasites with medical or agricultural importance, C. elegans seems to harm no one. Yet, this animal has attained a status in medical science that compares to more complex organisms such as the mouse or fruit fly in its utility for scientific discovery. It has been the subject of thousands of studies dealing with topics as diverse as nutrition, aging, and nervous system development. About 5000 scientists are now pursuing this single species in hundreds of laboratories worldwide. In 2002, the Nobel Prize in Medicine was awarded to three of the pioneers in establishing C. elegans as a “model organism“: Sydney Brenner, John Sulston, and H. Robert Horvitz. Why study worms?

Sydney Brenner first turned his attention to C. elegans in the 1960's. Working at the Medical Research Council in England, he was looking for a small animal with inexpensive tastes that could be easily cultured in the laboratory.

In a departure from traditional articles on Photoshop, this article will provide a look at how to save movies for the purpose of distribution to Macintosh, Windows and Linux operating systems.

More than once, I have been asked to produce and help with the distribution of digital videos that rival those downloadable trailers for big Hollywood productions. I kindly inform the clients that I do not have a staff large enough to tweak each individual frame of their video, and that their expectation must go down a few notches. Upon seeing their baffled look, an explanation ensues, much like what follows:

First of all, digital video must be compressed in order to run seamlessly from a computer. Only the most robust computers can keep up with the number of frames flashing by per second (-30 frames for NTSC), and even these cannot play back for extended periods of time without the loss of some frames (what is called dropped frames in the digital editing world).

The current use of microwave technology in science creates a dichotomy. Is it the heat or is it the energy? One entire branch of science, chemistry, uses microwave energy to apply heat to a broad range of chemical processes, under pressure, to produce the desired end-products quickly and efficiently (1). The biological sciences, surgical pathology in particular, have tried to adapt the microwave oven to speed up a broad range of processes: fixation, decalcification, antigen retrieval, tissue processing for paraffin and plastic embedding, and histological staining, including special stains, immunolabeling, and in situ hybridization (2). The biologists have assumed that they are also applying heat to speed processing. However, recent improvements in the microwave suggest that the energy is the critical variable (9). We have designed fixation experiments to test the two views.

One problem facing owners of high-end digital microscope cameras and scanners is dealing with 12-bit TIFF format images. Because of a vagueness in the TIFF specification [1], some prograins do not load 12-bit TIFF images at all, or do not handle them gracefully. Unfortunately, Adobe Photoshop is one such program.

A common problem with 12-bit images that do load in Photoshop is that the image appears to be totally black once loaded. This occurs when the camera stores the most significant bits of the image in the lower 12-bits of a 16-bit data space. Photoshop, when converting to its internal 16-bit representation, does not scale these properly, resulting in a low contrast image. This can present problems with viewing the images, or performing any processing or measurement steps that you might desire.

Technical publications sometimes include scanning electron images to characterize a microstructure, when the relevant structure could have very easily been illustrated using a simple light micrograph. When should one use a light generated image? What are the advantages/disadvantages of an electron generated image, particularly; one generated using a scanning electron microscope (SEM)? While there is some overlap in the capabilities of these imaging systems; in general, they are complementary tools, each with their own uses. Standards under the jurisdiction of ASTM Committee E4 on Metallography offer guidance to both new and experienced users of both investigative techniques.

Numerous studies have demonstrated that fungi are capable of colonizing a range of indoor construction and finishing materials as well as a number of air handling system components. Many of the species found are known to produce mycotoxins and demonstration of the presence of ‘toxic mould’ in both the workplace and in dwellings has become a major issue. Mould issues now are the focus of litigation or are currently in contention in a number of states and hundreds of millions of dollars are at stake.

The indoor environment harbors a variety of microorganisms, including bacteria and fungi. Under normal indoor conditions most of these organisms are present as dormant forms. The fungi persist either as conidia (asexual spores), sexual spores, or hyphal fragments. The presence of water in an environment may lead to the growth and proliferation of fungal species, sometimes resulting in deterioration of the colonized substrates with possible negative effects on IAQ.

Promoting and maintaining a facility is a major concern to many of us. I had the pleasure last spring of participating in the 2nd International Cryo-workshop held in the Bio-Imaging Facility at the University of British Columbia. I talked to the facility director, Elaine Humphrey, and saw what she has done in a relatively short number of years in building that facility. I was incredibly impressed so I asked Elaine if she would address mis topic.

Elaine started out as a marine biologist in England and came across a problem that required electron microscopy. The first facility she went to was very discouraging saying that it was an extremely difficult technique. She managed to find another facility that made it easy.

One of the methods of preparing samples for analysis by Transmission Electron Microscopy (TEM) is the well-known procedure using a Tripod polisher and the wedge technique (1-3), developed in our laboratory. Though developed explicitly for preparing samples of integrated circuit structures built on silicon, the technique has been used in our lab for a wide variety of other materials, including metals and ceramics. In general when working with silicon samples, we have the luxury of starting with large wafer pieces or chips that are generally at least a couple of millimeters square or larger. Recently, however, we needed to work for an extended period on GaAs based lasers, where the devices requiring analysis were individual lasers extracted from individual packages. These small samples, measuring 100x100x50 microns, are too small for the manual handling involved in routine mechanical cross sectioning methods.

There is no substitute for good microscope care. A unit that is stored and covered, with its lens protected in a constant temperature/ humidity environment, which is dust free (in the laboratory away from acid wash areas) speaks for itself. During cleaning, oculars in particular, microscope rubes should be covered to prevent entry of dust. A lens should be inspected with a view to cleaning if there is a lack of contrast, cloudiness or poor definition in the images it produces.

While extolling the virtue of cleaning microscope components, it should be emphasized that cleaning can cause considerable damage if it is done incorrectly.

Projects that require viewing dozens or hundreds of specimens often include countless hours for specimen preparation. Specimens are often affixed to metal or carbon stubs with conductive tape, paint or paste (Rampley, 1976; Witcomb, 1981). The use of conductive paint or paste requires substantial mounting and drying times prior to coating with conductive metal or carbon and observation in a scanning electron microscope (SEM). We here describe a simpler protocol for mounting specimens to expedite specimen preparation.

During a recent study, where cryofractured salmon egg membranes were mounted on edge to view transverse sections, we needed an expedient method of specimen mounting to quickly view hundreds of samples. We experimented with mounting specimens in metal putty, a product used by fishermen for weighting fishing line. The methodology described here solved some of the problems of messy specimen mounting and eliminated the need to wait for curing before coating and observation.

Very small samples (under 1 mm) prepared for SEM viewing can be sprinkled randomly on an adhesive-coated stub, or manipulated into position with various tools (fine forceps, pointed stick, cotton applicator, hair brush) under a magnifier or stereo microscope. None of these methods allows reliable, damage-free control over the orientation of the sample. Here follow plans for a simple, portable “Vacuum forceps” to create a mild vacuum th rough a micro-fme tip to hold and orient SEM samples as they are applied to the adhesive. It is also useful for sorting samples. Commercial vacuum forceps with on-board vacuum range in price from $500 to $900. This unit was built from new parts for under $100.

The vacuum pump is from a portable motorized pipetter, such as the Drurnmond Scientific Portable Pipet Aid, or Mano stat Mopet (Figure 1). We have used the Drummond 9V motor and pump assembly.