Fluorescence imaging techniques

While fluorescent imaging techniques offer very high sensitivity, there remains the problem of background noise arising from fluorescence from the sample itself (autofluorescence). There are two strategies to overcome this (i) two-photon excitation,32 and (ii) the use of phosphorescent... 

Quantitative fluorescence imaging techniques and FLIM in particular are becoming increasingly important in biological and biomedical sciences. Knowledge of instrumentation and data analysis is required to avoid misinterpretation of the experimental results and to exploit the wealth of information provided by these techniques. 

The mixed mode of sorption of the dye l,l -dioctadecyl-3,3,3, 3 -tetramethylindocar-bocyanine pechlorate (Dil) at the interface of an ODS stationary phase and ACN-water mobile phase was studied by single-molecule resolution and fluorescence imaging techniques. The measurements indicated that minimally four types of adsorption sites are present on the surface of the ODS stationary phase. The desorption times of the dye are different at the different adsorption sites resulting in a deformed peak shape [152],... 

Another important characteristic of photoreactive agents is their apparent affinity for certain targets that are of special interest for interventional vascular therapists, As most photosensitizers fluoresce, the kinetics of their distribution in vascular tissue can be investigated both at macroscopic and microscopic levels using fluorescence imaging techniques (Fig, 3), Numerous studies on porphyrin, chlorin, texaphryin, pheophorbide and phthalocyanine photosensitizers in various animal models have documented selective localization in... 

Colorimetric pH sensing has a long tradition and numerous chromogenic sensors such as phenolphthalein, bromothymol blue, methyl red, and many others, have been developed. These indicators are involved in protonation-deprotonation equilibria between two (or more) forms of different spectral properties. Much higher sensitivity can be obtained with fluorescent proton sensors. Furthermore, this technique can be widely used in bioanalytical chemistry, cellular biology, and medicine. Application of fluorescence imaging techniques provides spatial information on pH. 

There have been quite a few papers published which deal with fluorescence methods in prion research. Generally, three different approaches have been utilized. First, PrP chimeras with fluorescent proteins (e.g., green fluorescent protein, GFP) have been produced to study various aspects of cellular questions or protein folding. For example, fluorescence imaging techniques have been applied to study prion propagation in yeast (reviewed in [45]). Other examples concern attempts to study protein folding and the nature of aggregates. Kawei-Noma et al. analyzed the... 

Quantitative Fluorescence Imaging Techniques for the Study of Organization and Signaling Mechanisms in Cells... 

This applicability of equations 1-4 has been verified for many types of cells and lipid vesicles by fluorescence imaging techniques (7-9) and for the measurement of critical breakdown field strength (10-12). 

A clever and very powerful variant of this has been pioneered by Tsien and co-workers. A wide array of fluorescence imaging techniques are now available that allow one to directly monitor chemical processes in cells in real time. A good example of this is the collec-... 

A number of more sophisticated fluorescence imaging techniques are available. Fluorescence lifetime imaging microscopy (FLIM) exploits the fact that the excited state lifetime is sensitive to its microenvironment to provide a contrast mechanism for imaging. By imaging the fluctuations of an excited-state lifetime... 

In this chapter, the application of fluorescence imaging techniques to the structural analysis of polymer blend systems is discussed, and recent developments in fluorescence microscopy are described. 

Fluorescence microscopy can be used to identify the spatial distribution of individual components in a blend system by the selective fluorescence labeling of the specimen. Therefore, fluorescence imaging techniques have been widely used to study the domain structure at the length scale of micrometers [15-22]. In particular, without the use of confocal microscopy, it is difficult to obtain the detailed micrometer-order 3D data. The structural analysis in three dimensions for polymer blends is reviewed at this point. 

STED microscopy is a scanning confocal fluorescence imaging technique. As noted above, confocal microscopy illuminates the sample with a focused light, but the size of the focal spot is limited to approximately 200 nm by the diffraction limit. In STED microscopy, a donut-shaped STED spot is overlapped on the excitation spot, as shown in Figure 19.9. The STED beam has a wavelength oflsTED that... 

The concept of using visible-light activatable CO-releasing organic molecules with simultaneously generate fluorophores (42) has been proven by means of the micelle-encapsulated cyclic a-diketone precursors. These allow monitoring the delivery of carbon monoxide by fluorescence imaging techniques. ... 

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