Confocal emission wavelength

Of the five probes evaluated only Probes 1, 3, and 5 were worth evaluating in detail, as the others had small Stokes shift (excitation wavelength, /v, minus emission wavelength, /Vln) or no detectable emission. Fluorescence behavior was measured using a Zeiss LSM 510 Laser Scanning Confocal Microscope (LSCM) and an Ocean Optics USB2000 spectrometer. 

Fig. 2.18 A Confocal fluorescence microscope images of the QDs on (Aa) a flat gold film, (Ab) the conical Au array, and (Ac) the dimpled Au array. (Ad) 3D visualization of the fluorescence intensity in (Ac) [60]. The QD has an emission wavelength of 597 nm. The excitation laser source was a 543 nm HeNe laser. (B) Field snapshot image from FDTD simulation results of Au coated dimpled structure. (C) Plots for the near-zone field intensity versus time in the dimpled Au structure [60]. Reproduced with permission [60]. Copyright 2013, Royal Society of Chemistry...

For example, the Rayleigh scattering of UV wavelength photons is a particular problem in single-photon confocal microscopy [17]. Furthermore, another point to note is that the emission wavelength for MPM is substantially shorter than the excitation wavelength, which makes for easier differentiation and hence detection. 

In contrast, the emission wavelength for confocal microscopy is longer, but usually by only 50-200 nm. This results in more difficult detection in confocal systems. 

Fig. 8 The fluorescence image of Chenopodium album salt gland seen in laser-scanning confocal microscope. The excitation wavelength 488 nm, emission > 520 nm. A - single image of the gland slice B - stack of the slices (sum, resulting or composite image) of the gland.

Homo-FRET is a useful tool to study the interactions in living cells that can be detected by the decrease in anisotropy [106, 107]. Since commonly the donor and acceptor dipoles are not perfectly aligned in space, the energy transfer results in depolarization of acceptor emission. Imaging in polarized light can be provided both in confocal and time-resolved microscopies. However, a decrease of steady-state anisotropy can be observed not only due to homo-FRET, but also due to rotation of the fluorescence emitter. The only possibility of discriminating them in an unknown system is to use the variation of excitation wavelength and apply the... 

Fig. 7.6. A and B. Confocal laser scanning microscographs of schistosome adults showing auto-fluorescence 488 nm was used for excitation and 520 nm for emission. A. Mid-body of a male schistosome with the focus on the lumen of the bipartite gut (g). In bombarded worms, a pale auto-fluorescence sometimes occurs under in vitro culture conditions. This auto-fluorescence occurs over a wide spectrum of wavelengths.

Figure 14.10 Fluorescence spectra of FITC collected on die nanostructured gold (MEF, upper line) and on Si02 substrate (reference, lower line) by confocal microscopy. Both the curves were scaled so that the peak intensity of the reference emission was normalized to 1. The excitation wavelength was 458 nm.

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