Specimen preparation method drying methods

Preparation of dry hydrates. A general method to obtain a small specimen of a pme, dry hydrate from a moist product is to take the greater part of the product and dry it... 

Electron microscopic studies of fresh and used samples were provided with units EM-125K, Ukraine and JEM-IOOCX, Japan with a resolution of about 0.5 ran. Specimens for TEM-analysis were prepared by conventional methods with use both of dried suspension and extraction carbon replica. The identification of phases was performed with the help of ASTM (American Society for Testing and Materials, 1986). 

Walter and Bryant [414] described a method for freeze drying latex specimens in a home made vacuum system rather than a commercially available device (as was typical of the state of the art at that time). Later, a freeze drying/image analysis method using commercially available equipment was described [413]. Important details of that method included specimen preparation, placement onto a TEM (or SEM) grid, the hardware for the experiment and the metal coating. 

Finally, for critical point drying of polymers a suitable series of fluids and conditions must be chosen that will not damage the specimen. Carbon dioxide dissolves in epoxies and in polystyrene. Apparently long term high pressure exposure and then a sudden release can turn these polymers into popcorn. Microscopic comparison of a material prepared by a variety of different preparation methods is the best way to uncover any possible artifacts caused by the specimen preparation method. 

Purification of luciferase. Cypridina luciferase is more stable than many other luciferases, except that this enzyme is rapidly inactivated at acidity below pH 5.0. The dried specimens that have been stored for over 50 years at room temperature (sometimes exceeding 30°C) still possess strong luciferase activity that can be extracted and purified. Preparations of highly purified luciferase have been obtained by various methods (McElroy and Chase, 1951 Shimomura et al., 1961,1969 Tsuji and Sowinski, 1961 Stone, 1968 Tsuji etal., 1974 Thompson et al., 1989) the purification methods employed include... 

The specimen was prepared by the following method. After mixing HAF carbon black (50 phr) with natural rubber (NR) in a laboratory mixer, carbon gel was extracted from unvulcanized mixture as an insoluble material for toluene for 48 h at room temperamre and dried in a vacuum oven for 24 h at 70°C. We made the specimen as a thin sheet of the carbon gel (including carbon black) by pressing the extracted carbon gel at 90°C. The cured specimen was given by adding sulfur (1.5 phr) to the unvulcanized mixture and vulcanized for 30 min at 145°C. The dynamic viscoelastic measurement was performed with Rheometer under the condition of 0.1% strain and 15 Hz over temperatures. 

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. 

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