Microscopy magnification

Fig. 1. Mouse embryonic stem cells (ES-D3) after passaging (a) and cultured for 2 days, ready for passaging (b). Unstained, light microscopy, magnification 4x.

Fig. 3. Embryoid bodies at day 3 (a). Embryoid bodies at day 5 (b). Differentiated ceiis into contracting myocardiai ceiis at day 10 (c). Unstained, iight microscopy, magnification 4x.

Fig. 22.1 Erythrocytes of rats with sub-chronic poisoning by heavy metal salts, animal group 2 (a), and after treatment, animal group 3 (b). Light microscopy magnification x 40...

Fig. 22.2 Swelling and polymorphism of mitochondria, expansion of bile ducts, and appearance of lysosomes affected by heavy metals in group 2 animals. Electron microscopy, magnification X 7,500...

Fig. 22.5 Normalization of hepatocytes and ultrastmc-ture after the treatment course. Animal group 3. Electron microscopy, magnification x7500...

Figure 9. Three-day-old infection in wheat treated with Bayleton—germinating rust spore with an appressorium positioned above a stoma and two epidermal cells with hypersensitive reaction (fluorescence microscopy magnification X 190, photograph reduced 80%). (Reproduced with permission from Ref. 6. Copyright 1982 Pflanzenschutz-Nachrichten Bayer.)...

Microscopy Magnification of structures too small to be seen by the naked eye Visualization and identification of tissues, cells, and biomolecules... 

Optical Techniques. The most important tool in a museum laboratory is the low power stereomicroscope. This instmment, usually used at magnifications of 3—50 x, has enough depth of field to be useful for the study of surface phenomena on many types of objects without the need for removal and preparation of a sample. The information thus obtained can relate to toohnarks and manufacturing techniques, wear patterns, the stmcture of corrosion, artificial patination techniques, the stmcture of paint layers, or previous restorations. Any art object coming into a museum laboratory is examined by this microscope (see Microscopy Surface and interface analysis). 

The very high powers of magnification afforded by the electron microscope, either scanning electron microscopy (sem) or scanning transmission electron microscopy (stem), are used for identification of items such as wood species, in technological studies of ancient metals or ceramics, and especially in the study of deterioration processes taking place in various types of art objects. 

The impact of electron-optical instruments in materials science has been so extreme in recent years that optical microscopy is seen by many young research workers as faintly fuddy-duddy and is used less and less in advanced research this has the unfortunate consequence, adumbrated above, that the beneficial habit of using a wide range of magnifications in examining a material is less and less followed. 

In order to obtain higher magnification than is possible with light microscopy, by a ratio of 1000 to 1, instruments employing magnetically... 

Fig. 11. Optical microscopy of SD-loaded cross-linked xylan microcapsules at 40x magnification.

Transmission electron microscopy (TEM) The dispersion of cobalt oxide species on the titania supports were determined using a JEOL-TEM 200CX transmission electron spectroscopy operated at 100 kV with 100k magnification. 

The development of high-magnification microscopy made it possible to create images of biological materials at the molecular level. Many of these images show structures that have liquid crystalline aspects. Shown here are aligned mosaic virus molecules and protein molecules in voluntary muscles. In addition, all cell walls are picket fences of rod-shaped molecules in regular yet fluid arra. ... 

Fig. 6. Electron microscopy of Ca -ATPase crystals in thin sections. Sarcoplasmic reticulum (2mg of protein/ml) was solubilized in the standard crystallization medium with C12E8 (2mg/mg protein) and incubated under nitrogen at 2°C for 15 days. The crystalline sediment was embedded in Epon-Araldite mixture and processed for electron microscopy. Depending on conditions during fixation, embedding, sectioning and viewing, the observed periodicities in different specimens varied between 103 and 147 A. Magnification, x 207000. From Taylor et al. [156].

We use optical microscopy to examine samples at magnifications from about 5x up to approximately l,000x. Samples may be examined using either transmitted or reflected light, depending on the nature of the sample and the information that we are seeking. 

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