Light microscopy confocal fluorescence

It is interesting to note the analogy of developments in light microscopy during the last few decades. The confocal microscope as a scaiming beam microscope exceeds by far the nomial fluorescence light microscope in resolution and detection level. Very recent advances in evanescent wave and interference microscopy seem to promise to provide even higher resolution (B1.18). 

White, J. G., Amos, W. B. and Fordham, M. (1987). An Evaluation of Confocal Versus Conventional Imaging of Biological Structures by Fluorescence Light-Microscopy. J. Cell. Biol. 105, 41-8. 

Microscopic techniques, 70 428 Microscopists, role of, 76 467 Microscopy, 76 464-509, See also Atomic force microscopy (AFM) Electron microscopy Light microscopy Microscopes Scanning electron microscopy (SEM) Transmission electron microscopy (TEM) acronyms related to, 76 506-507 atomic force, 76 499-501 atom probe, 76 503 cathodoluminescence, 76 484 confocal, 76 483-484 electron, 76 487-495 in examining trace evidence, 72 99 field emission, 76 503 field ion, 76 503 fluorescence, 76 483 near-held scanning optical,... 

Shooton, D. (ed.) (1993) Electronic Light Microscopy. The Principles and Practice of Video-Enhanced Contrast, Digital Intensified Fluorescence, and Confocal Scanning Light Microscopy. Wiley-Liss, New York. 

The two cationic dyes, Py+ as a donor and Ox" as an acceptor, were found to be very versatile for demonstrating photonic antenna functionalities for light harvesting, transport, and capturing, as illustrated in Fig. 7. They can be incorporated into zeolite L by means of ion exchange, where they are present as monomers because of the restricted space. In this form they have a high fluorescence quantum yield and favourable spectral properties. The insertion of the dyes can be visualised by means of fluorescence microscopy. The fluorescence anisotropy of Ox -loaded zeolite L has recently been investigated in detail by conventional and by confocal microscopy techniques [15],... 

The structure (e.g., number, size, distribution) of fat crystals is difficult to analyze by common microscopy techniques (i.e., electron, polarized light), due to their dense and interconnected microstructure. Images of the internal structures of lipid-based foods can only be obtained by special manipulation of the sample. However, formation of thin sections (polarized light microscopy) or fractured planes (electron microscopy) still typically does not provide adequate resolution of the crystalline phase. Confocal laserscanning microscopy (CLSM), which is based on the detection of fluorescence produced by a dye system when a sample is illuminated with a krypton/argon mixed-gas laser, overcomes these problems. Bulk specimens can be used with CLSM to obtain high-resolution images of lipid crystalline structure in intricate detail. 

White, J.G., W.B. Amos, and M. Fordham. 1987. An evaluation of confocal versus conventional imaging of biological stmctures by fluorescence light-microscopy. J. Cell Biol. 105 41-48. 

Fig. 6 Adsorption of microcapsules onto the (PLL/HA)24/PLL films, (a-c) Confocal fluorescent microscopy images of the capsules exposed to the near-IR light irradiation, (d) CLSM image of the film surface (the film is prepared with PLL-FITC black lines are scratches made by a needle for easier film imaging), (e) Cross-sectional profile of the capsules after step-by-step laser exposure (the sections from top to bottom correspond to the images a-c, respectively), (f) Optical microscopy images of the capsules after light irradiation. Scale bars (a-c, f) 4 pm, (d) 25 pm. Reproduced from [100]...

As previously discussed, electron, light, and confocal microscopy techniques may be used to visualize the position of electron-dense precipitates, radioactive substances, and fluorescent probes, respectively, in the sample tissue. However, none of these techniques possess the capability both to visualize and to selectively measure the flux of a molecule across the skin. SECM, however, permits the measurement and subsequent imaging of the local flux of an electroactive species across biological membranes. Scott et al. [3] used SECM to investigate the effect of pretreatment of the penetration enhancer sodium dodecyl sulfate (SDS), on the ion transport rate and transport pathways of Fe(CN) across hairless mouse skin. Increasing the time of SDS exposure from 10 min to 30 min increased the overall (porous and nonporous) transport of Fe(CN) by 17-fold. More specifically, the SDS-induced increase in Fe(CN)g transport was found to be associated with nonporous (i.e., intercellular) transport routes, while transport via porous routes was significantly reduced. The fraction of Fe(CN)g transport through pores, as measured by... 

Masters BR, Kino GS. Charge coupled devices for quantitative Nipkow Disk real-time scanning confocal microscopy. In Shotton D, ed. Electron light microscopy The principles and practice of video-enhanced contrast, digital intensified fluorescence, and confocal scanning light microscopy. New York Wiley-Liss, 1993. 

Figure 1.49 shows an example of using confocal fluorescent microscopy to reveal microscopic features in a specimen. The specimen is low density polyethylene (LDPE) containing fluores-cently labeled silica particles. The particle size and distribution in the polymer matrix can be clearly revealed by 3D confocal microscopy. Thus, confocal microscopy provides us a new dimension in light microscopy for materials characterization, even though its applications in materials science are not as broad as in biology. 

Why are chemical stains required for visualizing cells and tissues with the basic light microscope What advantage does fluorescent microscopy provide In comparison to the chemical dyes used to stain specimens for light microscopy What advantages do confocal scanning microscopy and deconvolution microscopy provide in comparison to conventional fluorescence microscopy ... 

Light Microscopy. Light microscopy includes the use of transmitted light, reflected light, polarized light, fluorescence, and, more recently, techniques such as confocal microscopy. Each of these variations has particular strengths and applicability to suspensions. 

Figure 19. Correlated images of the same sample observed using cryogenic SEM (left) and scanning laser confocal light microscopy (right). The confocal image in fluorescent mode (right) shows a concentration of fluorescing components that correlates with the clay structure.

---