We know that material within a cell is “packaged” within the Golgi apparatus. These “packages” (vesicles) bud off from the trans face of the Golgi and proceed to their destination. Just what drives this budding off process is closer to being understood, thanks to a recent report by Steven Jones, Kathryn Howell, John Henley, Hong Cao, and Mark McNwen. They presented morphologic and biochemical evidence that dynamin plays a role in this process.

The dynamins are a family of 100-kD guanosine triphosphatases that are thought to be involved in the budding off of vesicles from the plasma membrane during endocytosis. Whereas some forms of dynamin are restricted to specific cells, such as neurons, the form known as dynamin II (Dyn2) is present in all tissues, including epithelium.

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.

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.

My previous article on digital imaging in the April 1997 issue of Microscopy Today noted the use of an Olympus Auto Bellows with a Kodak MegaPlus 1.6i/AB CCD camera for digital photomacrographs equivalent to 4 x 5 Polaroid prints with magnifications between 10X and 50X, The purpose of this article is to document the high resolution obtainable with the bellows system and the design modifications needed to eliminate the plastic dovetail inserts of the Olympus Auto Bellows, which are susceptible to delayed stress cracking when used with a heavier camera like the MegaPlus, Total failure of the dovetail inserts could cause costly damage to the lens and the camera.

Depending on the quality of the glass slide (not all brands seem to be the same quality and therefore display variable physical properties), post-polymerized specimen blocks can be separated from object slides. These can be of varying area size, and can include a selected area of your former semi-thin section or the whole area (as used in re-embedding techniques).

A few weeks ago, a person posted an interesting question on an internet microscopy mailing list: what is the difference between histogram stretching and histogram equalization when applied to microscopy images? The following is a short intuitive review which compares the two. Since this is a short and general description, I will gloss over some details and make some generalizations which may not be true in all cases and implementations.

The first thing to remember is the basic purpose of contrast enhancement. The idea is simple, In a grayscale (black and white) image you are simply trying to take two levels of gray that are close together, and thus visually similar, and move them apart so you can better see the difference between them. You can think of grayscale values in an image as beads on a string, Contrast enhancement simply moves all or some of those beads farther apart.

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.