In a clever application of time-lapse fluorescence microscopy, Li Wang, Scott Seeley, William Wickner, and Alexey Merz looked to see if there was membrane left over after vacuoles fused within a cell. Specifically, It is not known what happens when two vacuoles come together (this is referred to as “docking” ) and join together as one larger vacuole (“fusion“). For reference, the surfaces of the vacuoJes where they have joined is the “boundary” membrane, the membranes on the outside are the “outside” membranes, and the circular junction of the boundary and outside membranes is the “vertex.“

With the growing emphasis on nanotechnology, scanning probe microscopy (SPM) is emerging from the surface science laboratories and becoming a mainstream inspection and metrology tool along side optical and SEM microscopes. Scanning probe instrumentation and applications evolved dramatically during the past quarter-century (Table I). By 1998 SPM-related papers were being published at the rateof nearly 5000 per year Here we review the history of scanning probe microscopy, describe its current role as a critical enabler in nanotechnology, discuss why it has become a routine laboratory tool, and present a view of future directions for this advanced technology.

Many words have been written about filament saturation and filament life, not all with years of experience behind them] Sometimes when visiting laboratories one has the feeling that the life of the filament is far more important than the quality of the results, so let us try to demystify filament life?

The life of a tungsten hairpin filament very much depends upon its use and the applications present in a particular laboratory. Medturn to low magnification applications in the transmission electron microscope (TEM) may only require low emission currents (10 to 15 micro amps) with a long filament life resulting. High resolution studies require higher operating currents (20 to 45 micro amps) but, by demanding more emission current the life of the filament will suffer. Whilst a long filament life is good for the laboratory, it is not worthy of boasting, for those who have a short filament life may well be using the instrument near to the limit of its performance, a far more relevant boast!

This column is, perhaps, a departure from many techniques papers because the accompanying image chosen as “representative“ really is representative, rather than what is seen in many published papers in which the representative image is the one perfect image among hundreds of those that are biologically messy. The image used in this article to illustrate methods is not the best to use when creating regions of interest with Photoshop toots, for it contains elements which make the separation into regions of interest difficult to accomplish without reacquiring the image using better microscope techniques. I'm assuming that an image of this sort CAN bereacquired; if that isn't possible, some head-scratching and, perhaps a shift from a position of absolute accuracy to statistical accuracy might occur, and many would argue, should occur (since the whole matter is statistical anyway). Hopefully the investigator understands that, in some instances, human error can be as confounding as image processing error, except that image processing can create consistency. In other instances, artifacts in the images themselves cart cause too many wrong features to be measured, leaving humans as the best instrument.

TEM sample preparation using Focused Ion Beam (FIB) methods becomes more and more interesting for microscopists because the technique allows for reliable and very efficient sample preparation. The first application of TEM sample preparation by FIB-cutting was reported more than 10 years ago. Meanwhile, a lot of experience has been gathered that allows one to discuss the capabilities and limits of the FIB technique in detail.

Several TEM sample preparation techniques are known that all include FIB-cutting but differ in sample pre-preparation, sample handling, etc. This paper focuses on the actual FIB process, FIB tools are closely related to Scanning Electron Microscopes, but instead of an electron beam an ion beam (mostly Ga+ ions) is used to remove and deposit material.

Confocal microscopes have come a long way in the past decade. Not only are they more stable and easier to use than ever before, but their cost has dropped enough that multi-user facilities are finding competition from individual labs using the new breed of "personal" confocals. In fact it has, in some cases, become the de facto standard for fluorescence imaging regardless of whether the user actually has requirements for it or not.

But, researchers always have an ear out for something better. Enter 2-photon microscopy (2PLSM). The “bigger & badder” cousin of the confocal microscope has become a new weapon in the arsenal of a microscopy industry that caters to researchers who can't wait to fill their labs with the latest and greatest imaging systems. Advertised by the industry and researchers alike as a technique that seems to solve most of the problems that plague confocal, “2-photon” has become the new buzzword in the vocabulary of researchers eager to enhance their fluorescence applications.

Teaching and training users how to operate laboratory equipment is a time-intensive practice. Many new users are students, who have generally high turnover rates; after they complete a class project or degree program, they leave the facility, In addition, users often divide their time among a variety of techniques and equipment. With episodic usage, researchers tend to forget details of instrument operation and need to be retrained. Academic core facilities must balance their productivity against the time it takes to train and retrain an ever-changing parade of users. Site-specific multimedia teaching and training resources, such as films, CDs, videos, or DVDs, if easily available in the laboratory, would enable users to refresh and retrain themselves on equipment operation.

SEM users are familiar with two forms of contrast in SEM images: topographic contrast and atomic number contrast. We can now add a third form of contrast. Contrast can arise due to the different orientation of grains in the sample. However, in normal operation this con trast is very weak, since in the SEM the beam includes a range of incident angles. This has the effect of averaging out diffraction contrast from the different orientations of the grains. This contrast is generally much stronger when the trast is very weak, since in the SEM the beam includes a range of incident angles. This has the effect of averaging out diffraction contrast from the different orientations of the grains. This contrast is generally much stronger when the incident beam is an ion beam rather than an electron beam — contrast between the grains is strong in ion-beam images but not in normal SEM images.

Commonly known as 'water bears', tardigrades are a phylum of microscopic animals that can be found living on mosses and lichens all over the world. The name Tardigrada means 'slow walker' which describes their sluggish, deliberate movements. Between these slow movements and their 'teddy bear' like appearance, tardigrades are the only really “cute” invertebrate. Tardigrades, Echiniscus sp., are generally less than 500 micrometers in length and require at least40-power magnification to be seen clearly.

What is the best cantilever for intermittent contact mode (often called Tapping Mode™) atomic force microscope (AFM) imaging under water? This is a question I hear often and one that recently generated some interesting discussion on an AFM newsgroup (more on the newsgroup below). The ability of the AFM to image samples En physiologically relevant environments has made it a popular technique in the biological sciences. However, because scanning the AFM tip in contact mode easily perturbs many biological samples, it was the advent of intermittent contact modes that lead to AFM's widespread use in biology.