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Thermoelectrically Cooled Temperature-Gradient Apparatus for Comparative Cell and Virus Temperature Studies 总被引:2,自引:0,他引:2 下载免费PDF全文
Establishment of a near-linear temperature gradient in an incubator has been accomplished by the application of heat to one terminus of a conducting body, normally a metal bar, and the removal of heat from the other terminus of the conducting body. Such incubators have been complex and unwieldy because of the need for mechanical refrigeration. We have described a simplified temperature gradient incubator which uses thermoelectric module cooling coupled with electric heating. Along the gradient, 20 stations in two parallel rows of 10, each accommodating a 30-ml plastic cell culture flask, were continually monitored by an electronic thermometer, and the temperatures were recorded. By manipulation of two simple potentiometer controls, any temperature gradient between 0 and 50 C could be obtained. Minor deviations which occurred between theoretically perfect and obtained temperature gradients were reproducible and readily measured. The gradient incubator was particularly applicable to (i) simultaneously studying a given biological activity over the entire temperature range supporting the growth of a given cell, virus, or microorganism, or (ii) precisely defining the upper or lower temperature limits of a biological system by 10-point determinations. Preliminary experiments have demonstrated the usefulness of the apparatus in characterizing the temperature limits for growth in vitro of cells of reptilian cell lines. The gradient incubator was also successfully utilized for the characterization of the effect of temperature on the efficiency of plating of amphibian viruses and possible temperature variants of those viruses. 相似文献
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Eleanor M. Collins 《Biotechnic & histochemistry》1969,44(1):33-37
Carbon steel microtome knives etched with 0.1 N HNO3 for 2 min display a very sharp cutting edge. Over a period of 3 yr no damage to the steel has been detected. The effect on paraffin sectioning was observed by comparing acid-treated knives with nonetched but well-sharpened ones. Sections of whole eyes cut with an etched blade showed approximately 15% less compression of the parffin matrix than those sectioned with an untreated knife. Tissues selected from routine autopsy material presented approximately 9% reduction in compression. As a result, excellent ribbons of sections could be cut from 5-7 μ and floated on water at 42—46 C with a minimum of folds or distortion. Etching improved sectioning when knife edges having bevel angles in a range of 31-39° were used, and also when the bevel was decreased to 20°, but the 20° edge gave impractically short service. 相似文献
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Fred M. Uber 《Biotechnic & histochemistry》1936,11(3):93-98
Developments in the abrasive-ground glass type of microtome knife sharpener have been traced from 1857 to the present. Merits and disadvantages of each apparatus are critically discussed, particularly of the two practical power sharpeners, namely, the horizontal revolving disc and the vertical wheel. A new vertical wheel model, designed to facilitate the sharpening of long, sliding microtome knives, either with a chisel-shaped or a symmetrical bevel, is described. Notable mechanical features include: shaft rotation V-slots as sole adjustable part, thereby assuring accuracy of alignment; steel guide bar 45.7 cm. long; glass wheel mounted on its own axis, separate from motor; simple and sturdy construction with single casting constituting entire framework. 相似文献
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S. R. Shaw 《Biotechnic & histochemistry》1977,52(5):291-293
Electron microscopy-style fixation followed by epoxy plastic embedding is often now the method of choice for preparing tissue even for light microscopy; I have found it excellent for fluorescence, autoradiographic and conventional histology (Shaw 1972, 1977). Sections more than about five microns thick can be cut on a really sharp steel knife if the plastic is reasonably soft (Stretton and Kravitz 1973, Shaw 1972), but this is much easier and knife marks are reduced if extra-wide glass knives are used on a special-purpose intermediate microtome like the Sorvall JB-4. Recent budgetary restrictions made us defer purchase of such a microtome, and some alternative had to be devised. I report here a simple but rugged adapter for glass knives which replaces the steel knife in a conventional Leitz rotary microtome and allows thin plastic sections to be cut as easily as with a more sophisticated cutter. It could be adapted for any rotary microtome, and can be readily constructed in most machine shops for negligible cost. 相似文献
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Richard D. Campbell 《Biotechnic & histochemistry》1982,57(3):186-188
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G. L. Walls 《Biotechnic & histochemistry》1936,11(3):89-92
A method is described which combines the writer's hot celloidin technic1 with a form of the clearing-before-cutting procedure. The method requires only 16-17 days and yields a block which may be cut in any microtome, the sections being as thin as those afforded by paraffin with comparable material. The advantages of celloidin over paraffin, listed in the writer's earlier paper, are retained in the present method which, altho consuming more time than the hot process, requires less skill and gives superior results. 相似文献
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R. Semba 《Biotechnic & histochemistry》1979,54(5):251-255
Procedures for obtaining sections 1 μ thick on a conventional rotary microtome are described. Hydrophilic resin blocks with adequate hardness and elasticity for semithin sectioning are made by addition of divinylbenzene and methylmethacrylate to a commercial embedding kit. The blocks are pinched between two simple adapters and mounted in the specimen bolder of a microtome. A glass knife of the Ralph type with an effective blade length of 25 mm is made from a glass slide and attached to a metal bar with paraffin. The low cost assembly is set in the steel knife holder of a conventional rotary microtome. Sections I micron in thickness can be cut from the resin embedded blocks. Staining with the usual staining solutions may be weak due to the thinness of the sections, but the fine resolution and low distortion achieved are compensating gains. 相似文献
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Dale R. Disharoon M. Gary Wickham David M. Worthen Fred H. Lofftus 《Biotechnic & histochemistry》1983,58(3):143-151
The quality of sections obtained by microtomy depends to a large extent on the quality and characteristics of the microtome knife itself. Despite the need for improved microtomy techniques, there have been few significant developments since the introduction of glass and diamond knives in the 1950's. The manufacture of microtome knives from vitreous carbon provides new possibilities for developing both improved methods and improved equipment for specimen sectioning. Vitreous carbon has unique physical properties that lend themselves to the generation of precision cutting edges. Such an edge can be obtained either by breaking a piece of vitreous carbon or by using lapidary techniques. The resultant edge seems well adapted to both thick and thin sectioning. The introduction of vitreous carbon as a sectioning tool offers a significant alternative to metal, glass and diamond knives. 相似文献
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Sally B. Fand 《Biotechnic & histochemistry》1964,39(3):173-175
The antiroll plate is cut from a standard microscope slide, a 2 cm length, to give a 2 × 2.5 cm piece. This is fitted into inside grooves of a movable metal frame which is held by a hinge joint parallel to the back of the microtome knife. A stationary frame, which supports the hinged member, has spring clips welded to its sides for attachment to the knife. Clearance between the antiroll plate and knife is obtained by applying Scotch tape to the edge of the plate that is adjacent to the knife edge. The hinge permits the plate to be swung back and thus clear the knife surface. 相似文献
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P. J. Van Mullem 《Biotechnic & histochemistry》1961,36(4):229-232
The construction comprises a 0.3 hp electric motor, a drive mechanism which transforms the speed of the motor to the two actual cutting speeds, and a clutch mechanism which transmits the slow or the fast movement to the microtome. When the slow cutting speed is used the cam (on the microtome flywheel) and lever mechanism actuates the drive to give a quick return to the cutting position after a slow cutting act. This device, which needs little supervision, has given excellent serial sections, uniform both individually and with respect to others in the ribbon, with all the material on which it has been tested. 相似文献
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《Biotechnic & histochemistry》2013,88(6):375-376
A method of double embedding fixed tissues in 3% low viscosity nitrocellulose and paraffin is described. Five percent phenol in 80% alcohol during dehydration and 5% glycerin in the nitrocellulose solutions enhance cutting qualities. A modified Ruyter's solution is used to flatten sections. After a section is aflixed to a slide, it is passed through chloroform and acetone to remove the paraftin and celloidin. A 1% celloidin dip insures adherence of the seaion to the slide. Slides are stored in 70% alcohol until they are to be stained. Following staining and dehydration in graded alcohols, clearing should be done in a 1: 3 mixture of terpineol and toluene. 相似文献
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