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.

Preparation of digital figure plates for publication is best done with software designed for that purpose, such as QuarkExpress or Adobe Page-Maker, However, if you have only Photoshop in your repertoire, you can tackle page layout in the following ways.

This first method is probably easiest, but results in the loss of a few pixels along the inside edges of each of the images.

Asbestos fibers are commonly called ferruginous bodies due to the iron content of the fibers. After they are inhaled, the asbestos fibers become coated with glycoprotein and hemosiderin, deposited by macrophages.

This procedure may be used on either formalin fixed, paraffin embedded blocks or formalin fixed wet tissue. Because this procedure will result in complete destruction of the tissue sample used, it is very important to obtain written approval documenting this fact from the individual requesting this procedure, if the procedure is being done for someone else. The tissue should be from the lung parenchyma. Also, it is a good idea to use sterile, disposable tubes throughout this procedure to limit the possibility of contamination.

Those of us who study the structure and physiological function of ion transport cells in animals or their excised organs (gills, for example) are always interested in “quick and dirty” screening methods to identify ion transport epithelia. Having identified epithelial areas rich in putative “ionocytes”, we are also interested in looking at the mix of non-transport cells and “ionocytes” in the tissue. The so-called “silver staining” method can satisfy both of these desiderata quickly and easily.

Silver staining selectively blackens areas of the organism's body surface which are very permeable to chloride and/or silver ions; such areas are often the sites of ion transport epithelia (Croghan, 1958; Holliday, et al., 1990; Kikuchi & Shirashi, 1997).

When the workload is light, we like to hone our skills by performing analysis on difficult samples (or at least that's the justification for this particular diversion). During the long winter of 1996-97, we took up the challenge of imaging snowflakes using our scanning electron microscope (SEM). Snow, being both nonconductive and liquid at room temperature, provides some challenges to the microscopist.

We have a JEOL 5800LV, which when operating in “Low Vacuum” mode, can image nonconductive samples without charging. This is achieved by allowing a relatively high pressure in the sample chamber. The air in the chamber ionizes in the beam and neutralizes the charge buildup on the sample.

The surface of printed paper has been examined through a fully automated attenuated total reflection (ATR) mapping technique. Automated z-axis control was utilized to bring the sample into contact with the ATR objective in a reproducible manner and an integrated mapping stage was used to position the sample. A force sensing device, the Contact Alert, was used to ensure optimal contact between the sample and internal reflection element Global manipulations of the resultant data revealed compositional differences attributed to the printed ink, carbonate and cellulose distributions. These differences were clearly evident in the infrared, but not discemable in the visible. The bulk filler Kaolinite was identified as a post processing contaminate as well as a trace mixture of Dioctyl Phthalate and an aromatic acrylate.

A long time ago, we ciid some work on RBC's from muscular dystrophy patients, We found that the cells are very sensitive to pH, salt concentration, glass, and other things (maybe including the moon???), Low pH, increased salt, especially NaCl, and sitting in a glass tube or on a glass slide unfixed would cause echinocyte formation.

We got around the problem by drawing the blood and then IMMEDIATELY dropping (drop by drop) blood samples into 1% glutaraldehyde in phosphate buffer, pH 7.4 (not PBS). You can use a Maunsbach formula, where 0.135 U P04 gives 300 milliosmoles, or 0.1 M P04 plus sucrose (try 1.8 % sucrose). Test the osmolarity of the buffer; it should be 300 ± 10 or so. The final osmolarity of the buffered fix will be 400 milliosmoles; 300 from the buffer and 100 from the glutaraldehyde! The fix should be room temperature (not cold) when the blood is added. It can be stored refrigerated.