Phosphotungstic acid stain

Fig. 13. Schematic view of the periodic fine structure (phosphotungstic acid-stained) of the repeating elements of various reconstituted collagens native pattern, fibrous long spacing (FLS) collagen and segment long spacing (SLS) collagen. (From Schmitt et al., 1955.)...

Figure 15.6. Morphology of typical Polyamide/impact modifier blends — TEM., Phosphotungstic acid stain, top — PA-6/ethylene copolymer/ionomer blend (21,000X) bottom — PA-6/maleated EPR (3 1) blend (30,000X).

Figure 15.10. Morphology of PPE/PA-6 (60/40) blends (TEM, phosphotungstic acid stain) top — Uncompatibilized blend (lO.OOOX), bottom — Compatibilized blend (20.000X).

Figure 9.6 Transmission electron micrographs of (a) PS-300/PEMA-AIBN and (b) PS-190/PEMA-AIBN composite latex particles with a 40/60 weight ratio of seed to shell. The dark regions are polystyrene stained with RuOa and the lighter regions are acrylate domains outlined with phosphotungstic acid stain. (Reprinted from ref. 36. Copyright 1991 John Wley Sons, Inc.)...

Fig. 9.2 Spherulites in 0s04-inliltrated and phosphotungstic-acid-stained, compression-molded Nylon-6 (from Gal ski et al. (1988) courtesy of the ACS).

Phosphotungstic acid staining was used to show the fine structure in nylon 6 fibers [127] by soaking the fibers in 9-11% aqueous salt solutions and staining with 1.5 and 4.8% PTA. Longitudinal periodicities were shown for the stained fibers by TEM. However, the lamellae showed a change in size, depending on the concentration. 

Figure 8.22 Morphology of PA6/maleated LDPE (0.5% MA) blends [42]. (TEM, Phosphotungstic acid stain Top PA6/m-LDPE (60/40) blend Bottom PA6/m-LDPE (40/60) blend Note the phase inversion in...

Figure 8.27 Morphology of PA6/Zn lonomer/maleated SEES (55/25/20) blend [28]. (TEM, RUO4 and phosphotungstic acid staining)...

Figure 5.40. Transmission electron microscopy thin section of phosphotungstic acid stained cryosections of an as extruded (A) and deep drawn (B) coextruded film constructed of toughened nylon/barrier resin/tough-ened nylon. (From Wood [186] used with permission of the American Chemical Society Rubber Division.)...

For light microscopic examination, liver tissue was fixed in 10 % buffered formalin, embedded in paraffin, sectioned and stained with hematoxylin and eosin. In some cases, preparations were stained with PTAH (phosphotungstic acid-haematoxylin), by the Van Gieson method and the PAS (periodic acid-Schiff)... 

Fig. 1. Negative staining by phosphotungstic acid of Na,K-ATPase purified in membrane-bound form. The membrane surfaces are covered by particles arranged in clusters between smooth areas. From [2] procedure as described by Deguchi et al. [30].

Figure 6.4 TEM image of the dispersion of nanoparticles obtained after evaporation of the solvent of a nanoemulsion with an O/S of 70 30 and a water content of 90wt% and negative staining with a phosphotungstic acid solution. Reproduced with permission from [54].

The process of infection of lupine nodule cells by Rhizobia was examined by the thin-section electron microscopic technique, as well as the freeze-fracture technique. Different membranes such as infection thread membranes, peribacterioid membranes, plasma membranes, membranes of cytoplasmic vesicles, and membranes of the Golgi bodies and ER were stained with uranium-lead, silver, phosphotungstic acid, and ZIO (31). ZIO stained the membranes of the proximal face of the Golgi bodies and endoplasmic reticulum. ZIO staining has given good contrast in thick sections such as a cotyledon cell, a root cell, and an aleurone layer for ER, dictyosomes cisternae, mitochondria, and nuclear envelopes (17,32-37). 

TEM has been used to determine the shape and particle size of nanoparticles [27, 33]. Samples are prepared by placing a drop of preparation on copper grids, followed by negative staining with an aqueous solution of sodium phosphotungstate, phosphotungstic acid, or uranyl acetate [27, 163, 164]. Freeze fracturing with TEM has been... 

Figure 2. Photomicrographs (a) and (b) show low and high power views, respectively of a phosphotungstic acid hematoxylin-stained 5 yum thick section of lung from a mouse given a lethal dose of toxin-LR, and then killed when moribund. The arrow in (a) points to a thrombus in a pulmonary artery. The same thrombus is shown at higher magnification in (b). The thrombus consists of irregular clusters of small granules.

Staining techniques employing heavy metal compounds (e.g., uranyl acetate or phosphotungstic acid) as contrast agents have often been used to demonstrate the ) 2005 by CRC Press LLC... 

Figure 1-3 A cell of a Spirillum negatively stained with phosphotungstic acid. Note the tufts of flagella at the ends, the rough appearance of the outer surface, the dark granules of poly-(3-hydroxybutyric acid and the light-colored granules of unknown nature. Courtesy of F. D. Williams, Gail E. VanderMolen, and C. F. Amstein.

Fig. 2. Micrographs of PSI-enriched particles from/5. laminosum after negative staining with 2% (w/v) phosphotungstic acid. Magnification were (A)25,000x and(B) 160,000x.

Fig. 5-16 Schematic diagram showing how the staggered arrangement of tropocollagen molecules gives rise to cross-striations in a fibril negatively stained with phosphotungstic acid.

Fig. 4. Disruption of the synapsin-dependent vesicle pool by presynaptic microinjection of synapsin antibodies in the lamprey reticulospinal synapse. (A) Electron micrograph of a control synapse. (B) A synapse in an axon injected with synapsin antibodies. The axon was lightly stimulated (1 Hz for 12 min) and allowed to rest for 90 min before fixation. Note that a narrow rim of vesicles remains in the antihody-injected synapse. (O Immunogold staining of a reticulospinal synapse with synapsin antibodies. Note that the vesicles adjacent to the presynaptic membrane are almost devoid of gold particles. (D) Visualization of the filamentous cytomatrix that overlaps with the synaptic vesicle pool that remains after perturbation of synapsins. The electron micrograph shows a synapse in a normal axon (i.e. no microinjection or stimulation had been performed) stained with phosphotungstic acid (Gustafsson et al., 1996). The filamentous eytomatrix (arrowheads) at the presynaptic membrane is visible, but not the synaptic vesicle cluster. Designations as in Fig. 1. Scale bar, 0.2 p.m. Reprinted from Brodin et al. (1995) Eur J Neurosci 9 2503-2511, with permission.

The hbrillary astrocytoma is more common than the protoplasmic astrocytoma. " Fibrillary astrocytomas are a mixture of cellular processes (fibrils) and nuclei of greater angularity and density than normal or reactive astrocytes (Fig. 20.13 see Fig. 20.1 IB). They contain more intracytoplasmic fibrils, and their cellular processes are longer than those in protoplasmic astrocytomas. Thus, only the fibrillary astrocytoma stains well with phosphotungstic acid hematoxylin (PTAH), which stains fibrillar protein arrays, whereas both... 

Rat tail tendon (RTT) fibril stained with phosphotungstic acid (PTA), reprinted from Hall (95). The stained bands are labelled after Schmitt and Gross (191). Dots mark bands a to e, reading up. 

Band structure is more open and accessible than that of interbands to chemical invasion, as long as fibrils remain intact. Consequently, such experiments as the introduction of 8-naphthalene sulfonic acid without destruction of fibrillar structure, indicated by the lack of great reduction in shrinkage temperature, provide presumptive evidence that the basic side chains are accessible at band localities. More directly, the heavy anions of phosphotungstic acid can be seen in electron micrographs to locate at bands, possibly because of attraction to and accessibility of the basic side chains. Diffraction evidence that this stain and also hexametaphosphate enter bands almost exclusively was also obtained (23). 

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