Permanent mounts, preparation

An air bag from a 1991 Chevy was tom down in preparation for this book. As presently constructed, air bag detonators are sealed in such a manner that their removal and deployment is an arduous, often unrewarding Chore. At 800 each as dealer replacement parts, these caps are probably not practical for this use. Nevertheless, it seems typically inconsistent for the government to attempt to regulate purchase of blasting caps and then require that between one and four of them be permanently mounted in a vehicle carrying one s family about town. 1 won t even aDow my wife and children to ride in the same vehicle with commercial blasting caps ... 

Mounting of immuno-PAP wholemounts can be done as in Note 39 using glycerin, methylsalicylate, Permount, or resin, such as Durcopan ACM (depending on whether they are to be permanently mounted). Metal holders with coverslips on each side (outlined in Note 39) are practical since preparations can be viewed from both sides. Glycerin or methylsalicylate are useful nonpermanent mounting media if one wants to reorient the preparations or take them to subsequent treatments... 

A list of common permanent mounting media is given in Table 11-2, followed by names and addresses of some of the companies specializing in commercial thin-section preparation (Table 11-3). 

Van der Meer J. 1977. Optical clean and permanent whole mount preparation for phase-contrast microscopy of cuticular structures of insect larvae. Dros. Info. Services 52 160. 

Permanent stains of fecal smears are most needed for the detection and identification of protozoan trophozoites, but they are also used for the identification of cysts. Wet mounts of fresh feces, even with stains such as methylene blue, are not as sensitive for trophozoites and therefore do not substitute for permanent stains. It is sometimes difficult to identify cysts which are detected in wet mounts thus, for each specimen, regardless of consistency, it may be worthwhile to fix a portion in PVA fixative or to prepare two fecal films fixed in Schaudinn fixative so that permanent stains can be performed if needed. Permanent stains also provide a permanent record and are easily referred to consultants if there are questions on identification. 

Continue with Subheading 3., step 18 in the method. The positive reaction product with this chromogen will be red, with the nuclei a light blue. Rather than dehydrating the specimens in ethanol and xylene, allow them to dry, add 1 drop of Crystal/Mount (Biomeda Corp, Foster City, CA) to the specimen and bake them in a 60°C oven for 30 min. This preparation is permanent and can be cover-slipped with Permount if needed. The Crystal/Mount will form a hard plastic coating on the slide, but it can be damaged by smudging. 

Polished sections and polished thin sections are prepared according to the usual techniques of coal petrography. They are mounted permanently on quadrangular pieces of transparent Lucite for location purposes. We have described elsewhere a graphical method of micro-surveying which allows an observer to locate any specific autoradiograph on nuclear emulsion plate of a given point in an opaque section (13). 

Fading of fluorochromes. General tissue architecture is not visible. Preparations not permanent. Fluorescence microscope required. However, newer, brighter fluorochromes are more resistant to fading, especially when used with anti-fade mounting media. 

Produce permanent preparations by mounting in an aqueous-based medium, such as Immu-mount, or in a xylene-based mounting medium, such as Fluoromount, following dehydration through an ethanol senes (i.e., 5 min each in 10, 20, 30, 40, 50, 60, 70, 80, and 90% ethanol in distilled water followed by three 5-min steps in absolute ethanol see Note 4). 

Replicas of gratings can be made successfully and can provide excellent resolution and high reflection efficiency and definition. They usually have somewhat higher scattered light properties than do originals. Most producers of replica gratings do not make the details of their processes available. One method, however, is to prepare a collodion solution, flow it over a grating, allow it to set, strip it off, and mount it on a permanent base. 

HRP is not a fluorescent tracer (it generates a dense brown reaction product as outlined below), but has the advantage of producing permanent preparations and can be used in combination with whole-mount in situ hybridization techniques. 

To prepare fine museum-quality, permanent slides, it is best to mount specimens in Canada Balsam. Canada Balsam is usually supplied as a solution in xylene, although it is sometimes supplied solid and must be dissolved in xylene ( 60-65% [w/v]) before use. With use, the concentration of xylene in a stock of Canada Balsam decreases, and it is necessary to add more xylene. It is difficult to give precise recipes for Canada Balsam, because every user seems to prefer a slightly different viscosity. We tend to use a rather dilute solution of Canada Balsam so that it spreads easily and does not dry too rapidly while mounting specimens. The disadvantage is that there is actually less Balsam in a drop of the solution, and when dried, it may contract from the sides of the coverslip, sometimes even disturbing the specimen. Unfortunately, there is no substitute for experience when using Canada Balsam. 

Mounting media any available permanent resinous medium for DAB/hematoxylin-stained preparations fluorescence-free aqueous mounting media for fluorescence or confocal laser microscopy (e.g.. Fluorescent Mounting Medium, Dako). 

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