Contrast light microscopy

Figure 5.19 Vesicle-encapsulated microtubes in bolaamphiphiles with oligoglycine head groups (33) observed using phase contrast light microscopy (a, b) in water at 25°C and (c) after vacuum drying. Reprinted from Ref. 53 with permission of Wiley-VCH.

Several of these poly (vinyl chloride-g-2-ethylhexyl acrylate/acrylonitrile) films were examined by phase contrast light microscopy, and none showed evidence of two phases, i.e., there were no suspended phases larger than 0.25-0.50. ... 

Phase contrast light microscopy has been applied extensively to the analyses of unfilled binary elastomer combinations. This method is based on differences in the refractive indices of the polymers and has been reviewed by Kruse (1973). CaUan et al. (1965,1971a), and Scott et al. (1969) have shown the versatility of... 

Leave for 5 min (to swell) then mechanically homogenize using a Kontes Dounce tissue grinder (IS ml), assessing nuclear release by phase contrast light microscopy. 

Briefly fix or stabilize the cells by replacing culture medium with a solution of 1.0% (w/v) paraformaldehyde, 0.01% (v/v) glutaraldehyde in PBS for 1 min, followed by extraction with 0.5% (v/v) Triton X-100, also in PBS. The time of extraction varies with the cell line used (1-3 hr for Xenopus tissue culture cells, 4-5 hr for mammalian tissue culture cells). Extraction can be monitored with phase-contrast light microscopy, and a clear separation between the nucleus and the extracted cytoplasm is the desired end point. 

Phase contrast light microscopy has been applied extensively to the analyses of unfilled binary elastomer combinations. Ihis method is based on differences in the refractive indices of the polymers and has been reviewed by Kruse [27a]. Callan et al. [27b-d] have shown the versatility of the method for a wide range of binary blends containing NR, SBR, BR, CR, NBR, EPDM, HR, and CIIR. The results of these experiments are shown in Table III, which lists the measured areas of the disperse phase in more than 50 combinations of Banbury-mixed 75/25 binary blends containing eight different elastomers. Blends of IIR-CIIR and SBR-BR are excluded since the contrast was low. It can be seen that NBR produced the greatest heterogeneity in all blends except those with CR. 

Details are given of the production of a biodegradable lactide-caprolactone copolymer nanofibrous scaffold by electrospinning. Interactions between the scaffold and human coronary artery smooth muscle cells were demonstrated via MTS assay, phase contrast light microscopy, SEM, immunohistology assay and laser scanning confocal microscopy. 34 refs. 

Figure 7.5 Morphologies of bacterial cells containing PHA granules in the cytoplasm. A phase contrast light microscopy picture of Comamonas acidovorans cells containing 38 wt% of the dry cell weight (DCW) P(3HB-co-71% 3HV).

However, usually by the use of phase contrast light microscopy techniques, membrane aspects have been observed that hint towards submicroscopic structures of the fluid membranes. Examples are localized stable wiggles in tubular vesicles [12] and an abundance of tethers in many samples. Conflicting results in the context of the induced adhesion [18,19] suggested a fine superstructure of fluid membranes with an additional hidden area [20,21], superimposed on the well-known undulations [22], The existence of so-called dark bodies [23] in almost any of the lipid systems investigated and their formation processes (see below) implied the assumption that they are developed by the association of very small bilayer particles dispersed in the aqueous volume. Typical examples of dark bodies are shown in Figure 17.1 for DGDG. 

Using difference contrast light microscopy and laser confocal scanning microscopy, the presence of giant vesicles could clearly be observed in the oleic acid-... 

Fig. 2. Virus growth curve of wild-type WEE virus in A. albopictus (strain C6/36) cells. Cultured monolayers were washed once with PBS and then infected with virus at 5 PFU/cell. After adsorption for 90 min at 28°C the inocula were removed, mono-layers were washed three times with PBS, and culture medium was added. Infected cultures were incubated at 28°C. The samples of culture fluid were taken at the indicated times for plaque assay on CEF monolayers at 34°C. After 10 days, the infected cultures were split weekly at 1 5 or 1 10. The lower panels show uninfected and WEE virus-infected C6/36 cells photographed with phase contrast light microscopy (B. Simizu and S. Maeda, unpublished data).

Figure 7.5 Morphologies of bacterial cells containing PHA granules in the cytoplasm. A Phase contrast light microscopy picture of Comamonas acidovorans cells containing 38 wt.% of the dry cell weight P[3HB-co-71% 3HV]. B Freeze-fracture electron micrograph of the same sample. The fracture process was carried out at -160 "C. N - needle-type M - mushroom type S - crater like holes in the cell cytoplasm resulting from granules that have been completely scooped out...

A major objective of microstructural analyses on multiphase and other polymers is failure analysis, that is, determination of the mode or cause of failure, especially of a product in use in the marketplace. Failure analysis generally involves characterization of a material that has failed, either in service or in a physical test. Controls are not always available, and timing is often critical. In some cases, the types of analysis required may well be similar to those described above phase contrast light microscopy, PLM, SEM, TEM, and AFM. Other microstructural techniques that are valuable in solving such materials problems are chemical contrast imaging and elemental x-ray mapping. 

Fig. 3.4.4. Enhancement ofthin uncovered asbestos fiber detec- Fig. 3.4.7. Ferruginous body in the bronchoalveolar lavage tion using phase-contrast light microscopy. Lung tissue of a fluid of a talc crusher Turk with environmental/domestic exposure to tremolite...

Microscopy. Particle size, shape and structure of emulsion droplets can be visualized by various microscope techniques, such as phase contrast light microscopy, confocal scanning light microscopy (CSLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray microtomography (XRT), atomic force microscopy (AFM) and imaging techniques. 

---