Phase contrast optical microscopy

The sample used for a demonstration of broadband TPF imaging with compressed PCF supercontinuum in Figure 7.17 was a commercially available test slide (Invitrogen FluoCells , prepard slide 1, containing labeled bovine pulmonary artery endothelial cells). The conventional optical phase-contrast microscopy image... 

Optical and Electron Microscopy. Samples of film for optical and electron microscopy were prepared by microtoming. The samples for optical phase contrast microscopy were approximately 15-20jU thick whereas those for electron microscopy were ultra microtomed with a diamond knife to about 0.05-0. lju, thickness. A Leitz Ortholux microscope was used for the phase contrast microscopy and an RCA-EMU-36 electron microscope at 40,000 X magnification was used for the electron microscopy. 

Optical microscopy on phase contrast mode allows observation of the different morphologies obtained for each PP/interfacial modifier/PA6 blend. By image analysis techniques, it is possible to carry out statistical field measurements not only of the mean number of particles on the dispersed phase but also of their preferential geometry, mean size, and size distribution. 

Optical microscopy (OM), polarized light microscopy (PLM), phase contrast microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and scanning transmission electron microscopy (STEM) are the methods normally used for identification and quantification of the trace amounts of asbestos fibers that are encountered in the environment and lung tissue. Energy-dispersive X-ray spectrometry (EDXS) is used in both SEM and TEM for chemical analysis of individual particles, while selected-area electron diffraction (SAED) pattern analysis in TEM can provide details of the cell unit of individual particles of mass down to 10 g. It helps to differentiate between antigorite and chrysotile. Secondary ion mass spectrometry, laser microprobe mass spectrometry (EMMS), electron probe X-ray microanalysis (EPXMA), and X-ray photoelectron spectroscopy (XPS) are also analytical techniques used for asbestos chemical characterization. 

Walters and Keyte [102] first observed dispersed particles in blends of rubber pol)m[iers by phase contrast optical microscopy. Marsh et al [103] studied elastomer blends by both optical phase contrast and TEM. Electron microscopy was applied to study blends of natural rubber, st)n-ene-butadiene rubber (SBR), a s-polybuta-diene (PB) and chlorobutyl rubber [104]. It became obvious that both hardening of the... 

As stated at the beginning, some electrically neutral biological model membranes have been investigated for spontaneous and induced adhesion. The materials were swollen in water and the resulting structures involving single membranes were observed in optical phase contrast microscopy. 

In the second half of the 20th century, a number of advanced variants of optical microscopy were invented. They include phase-contrast microscopy (invented in France) and multiple-beam interference microscopy (invented in England), methods... 

Optical microscopy, such as phase contrast or differential interference contrast. 

Powerful methods that have been developed more recently, and are currently used to observe surface micro topographs of crystal faces, include scanning tunnel microscopy (STM), atomic force microscopy (AFM), and phase shifting microscopy (PSM). Both STM and AFM use microscopes that (i) are able to detect and measure the differences in levels of nanometer order (ii) can increase two-dimensional magnification, and (iii) will increase the detection of the horizontal limit beyond that achievable with phase contrast or differential interference contrast microscopy. The presence of two-dimensional nuclei on terraced surfaces between steps, which were not observable under optical microscopes, has been successfully detected by these methods [8], [9]. In situ observation of the movement of steps of nanometer order in height is also made possible by these techniques. However, it is possible to observe step movement in situ, and to measure the surface driving force using optical microscopy. The latter measurement is not possible by STM and AFM. 

Optical microscopy (OM) Reflection Transmission Phase contrast Polarized light... 

In electron microscopy as in any field of optics the overall contrast is due to differential absorption of photons or particles (amplitude contrast) or diffraction phenomena (phase contrast). The method provides identification of phases and structural information on crystals, direct images of surfaces and elemental composition and distribution (see Section H below). Routine applications, however, may be hampered by complexities of image interpretation and by constraints on the type and preparation of specimens and on the environment within the microscope. 

Fig. 12. Phase-contrast optical microscopy images after mixing phosphatidyl-cholesterol based liposomes bearing the complementary guanidinium and phosphate moieties...

Analogous results were also obtained microscopically. Interactions occurred spontaneously and large aggregates were formed, which were visible with phase contrast optical microscopy. These particles interact further giving rise to even larger aggregates, which in certain cases encapsulate smaller aggregates. 

Preliminary examination of the latex involved centrifugation and optical microscopy. Only a marginal tendency to fractionate was noticed after 2 hr of centrifuging several 10-ml samples. The approximate diameter of particles separable by normal centrifuging was near 0.5 fi. An optical microscope was equipped with an oil immersion lens (1000 X) and a phase contrast stage. The polymer particles were noticeable but only marginally visible. Their diameters were near the threshold of reso-... 

Figure 1.32 Optical arrangement of phase contrast microscopy. Shading marks the paths of diffracted light. (Reproduced with permission from D.B. Murphy, Fundamentals of Light Microscopy and Electronic Imaging, Wiley-Liss. 2001 John Wiley Sons Inc.)...

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