Imaging multiphoton

MALDI MCM-41 MCR MD ME MEM MI MPM MRI MS MVA Matrix-assisted Laser Desorption/Ionization Mobile Crystalline Material-41 Multivariate Curve Resolution Molecular Dynamics Matrix-enhanced Magnetic Force Micrscopy Multivariate Image Multiphoton Microscopy Magnetic Resonance Imaging Mass Spectroscopy Multivariate Analysis... 

Wokosin D L, Centonze V, White J G, Armstrong D, Robertson G and Ferguson A I 1996 All-solid-state ultrafast lasers facilitate multiphoton excitation fluorescence imaging IEEE J. Sel. Top. Quantum Electron. 21051-65... 

From these vievqjoints, we have developed a femtosecond NIR laser microscope with a home-built cavity dumped chromium forsterite (Cr F) laser as an excitation light source whose output wavelength is centered at 1260 run. In the following the set-up of the NIR laser microscope and its application to multiphoton imaging are presented. 

Multiphoton Fluorescence Imaging with the Near-Infrared 35 fs Laser Microscope... 

The NIR femtosecond laser microscope realized higher order multi photon excitation for aromatic compounds interferometric autocorrelation detection of the fluorescence from the microcrystals of the aromatic molecules confirmed that their excited states were produced not via stepwise multiphoton absorption but by simultaneous absorption of several photons. The microscope enabled us to obtain three-dimensional multiphoton fluorescence images with higher spatial resolution than that limited by the diffraction theory for one-photon excitation. 

Fig. 4.1. Multiphoton fluorescence intensity (A-C) and TCSPC fluorescence lifetime images (D-F) of fresh unstained sections of human cervical biopsy excited at 740 nm and imaged between 385 and 600 nm. The individual acquisition times were 600 s. Adapted from Fig. 22.11 of Ref. [8].

Since TIRF produces an evanescent wave of typically 80 nm depth and several tens of microns width, detection of TIRF-induced fluorescence requires a camera-based (imaging) detector. Hence, implementing TIRF on scanning FLIM systems or multiphoton FLIM systems is generally not possible. To combine it with FLIM, a nanosecond-gated or high-frequency-modulated imaging detector is required in addition to a pulsed or modulated laser source. In this chapter, the implementation with of TIRF into a frequency-domain wide-field FLIM system is described. 

The introduction and diversification of genetically encoded fluorescent proteins (FPs) [1] and the expansion of available biological fluorophores have propelled biomedical fluorescent imaging forward into new era of development [2], Particular excitement surrounds the advances in microscopy, for example, inexpensive time-correlated single photon counting (TCSPC) cards for desktop computers that do away with the need for expensive and complex racks of equipment and compact infrared femtosecond pulse length semiconductor lasers, like the Mai Tai, mode locked titanium sapphire laser from Spectra physics, or the similar Chameleon manufactured by Coherent, Inc., that enable multiphoton excitation. 

Peter, M. and Ameer-Beg, S. M. (2004). Imaging molecular interactions by multiphoton FLIM. Biol. Cell 96, 231-6. 

Qu, X., Wang, J., Zhang, Z., Koop, N., Rahmanzadeh, R. and Huttmann, G. (2008). Imaging of cancer cells by multiphoton microscopy using gold nanoparticles and fluorescent dyes. J. Biomed. Opt. 13, 031217. 

Diaspro, A. E. (2007). Special Issue Advanced multiphoton and fluorescence lifetime imaging techniques. Microsc. Res. Tech. 70, 397-492. 

Bacskai, B. J., Hickey, G. A., Skoch, J. etal. Four-dimensional multiphoton imaging of brain entry, amyloid binding, and clearance of an amyloid-beta ligand in transgenic mice. Proc. Natl Acad. Sci. USA 100 12462-12467, 2003. 

Mach-Zehnder interferometer, 144 Medical applications, 153 Metal-insulator transitions, 52 Monte Carlo procedure, 135 Multi-energy X-ray imaging, 131 Multilayer targets, 131 Multiphoton absorption, 85 Multiphoton ionization, 82 Multiple filamentation, 91, 92 Multipulse techniques, 152... 

See also Luminescent dendrimers antibacterial, 26 799 biocompatibility studies of, 26 800-801 in catalysis, 26 805-806 in cell targeting, 26 797-798 as chelators, 26 806-807 core and interior shells of, 26 789 cytotoxicity of, 26 800-801 in drug delivery, 26 792-795 in gene transfection, 26 791-792 as imaging agents, 26 795-797 luminescent, 26 801-804 medical applications of, 26 791-801 micelle-mimetic behavior of, 26 789 multiphoton applications of, 26 803-804... 

One attractive possibility is to develop CPs that can be used for in vivo imaging of protein aggregates. In this regard, the synthesis of appropriately functionalized CPs that are able to cross the blood-brain barrier (BBB) has been exemplified [36]. Such dyes can be utilized in powerful multi-photon imaging applications as previously reported CPs have been shown to have an excellent cross-section area compared with small fluorescent dyes, making these molecules suitable for multiphoton applications [33, 37]. 

SYTO 9 stained fluorescence was imaged using a Leica TCS SP2 AOBS multiphoton confocal microscope. 

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