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Two-photon Fluorescence (two-photon + fluorescence)
Terms modified by Two-photon Fluorescence Selected AbstractsIntracellular Imaging of HCV RNA and Cellular Lipids by Using Simultaneous Two-Photon Fluorescence and Coherent Anti-Stokes Raman Scattering MicroscopiesCHEMBIOCHEM, Issue 12 2006Xiaolin Nan Hepatitis C virus (HCV) infection is associated with changes in host-cell lipid metabolism. Here we describe a new approach for detecting HCV RNA using two-photon fluorescence (TPF), and HCV-associated changes in cellular lipids using coherent anti-Stokes Raman scattering (CARS) microscopy. By combining the two types of microscopy with a common laser source, we visualized both phenomena simultaneously and profiled cellular lipids and subcellular localization of RNA in real time. [source] Cell Signaling and Trafficking of Human Melanocortin Receptors in Real Time Using Two-photon Fluorescence and Confocal Laser Microscopy: Differentiation of Agonists and AntagonistsCHEMICAL BIOLOGY & DRUG DESIGN, Issue 4 2006Minying Cai Melanocortin hormones and neurotransmitters regulate a vast array of physiologic processes by interacting with five G-protein-coupled melanocortin receptor types. In the present study, we have systematically studied the regulation of individual human melanocortin receptor wild subtypes using a synthetic rhodamine-labeled human melanotropin agonist and antagonist, arrestins fused to green fluorescent protein in conjunction with two-photon fluorescence laser scanning microscopy and confocal microscopy. Stimulation of the melanocortin receptors by its cognate agonist triggered rapid arrestin recruitment and receptor internalization for all four human melanocortin receptors examined. Antagonists-bound melanocortin receptors, on the other hand, did not recruit , -arrestins, and remained in the cell membrane even after long-term (30 min) treatment. Agonist-mediated internalization of all melanocortin receptor subtypes was sensitive to inhibitors of clathrin-dependent endocytosis, but not to caveolae inhibitors. In summary, agonist-mediated internalization of all subtypes of melanocortin receptors are dependent upon ,-arrestin-mediated clathrin-coated pits, whereas, ,-arrestin-2 conjugated green fluorescence protein (,-arrestin-2-GFP) recruitment is not dependent on protein kinase A activation. Real time two-photon fluorescence laser scanning microscopy is a most powerful tool to study the dynamic processes in living cells and tissues, without inflicting significant and often lethal damage to the specimen. [source] Hybrid Rayleigh, Raman and two-photon excited fluorescence spectral confocal microscopy of living cellsJOURNAL OF RAMAN SPECTROSCOPY, Issue 6 2010Vishnu Vardhan Pully Abstract A hybrid fluorescence,Raman confocal microscopy platform is presented, which integrates low-wavenumber-resolution Raman imaging, Rayleigh scatter imaging and two-photon fluorescence (TPE) spectral imaging, fast ,amplitude-only' TPE-fluorescence imaging and high-spectral-resolution Raman imaging. This multi-dimensional fluorescence,Raman microscopy platform enables rapid imaging along the fluorescence emission and/or Rayleigh scatter dimensions. It is shown that optical contrast in these images can be used to select an area of interest prior to subsequent investigation with high spatially and spectrally resolved Raman imaging. This new microscopy platform combines the strengths of Raman ,chemical' imaging with light scattering microscopy and fluorescence microscopy and provides new modes of correlative light microscopy. Simultaneous acquisition of TPE hyperspectral fluorescence imaging and Raman imaging illustrates spatial relationships of fluorophores, water, lipid and protein in cells. The fluorescence,Raman microscope is demonstrated in an application to living human bone marrow stromal stem cells. Copyright © 2009 John Wiley & Sons, Ltd. [source] Antecedents of two-photon excitation laser scanning microscopyMICROSCOPY RESEARCH AND TECHNIQUE, Issue 1 2004Barry R. Masters Abstract In 1931, Maria Göppert-Mayer published her doctoral dissertation on the theory of two-photon quantum transitions (two-photon absorption and emission) in atoms. This report describes and analyzes the theoretical and experimental work on nonlinear optics, in particular two-photon excitation processes, that occurred between 1931 and the experimental implementation of two-photon excitation microscopy by the group of Webb in 1990. In addition to Maria Göppert-Mayer's theoretical work, the invention of the laser has a key role in the development of two-photon microscopy. Nonlinear effects were previously observed in different frequency domains (low-frequency electric and magnetic fields and magnetization), but the high electric field strength afforded by lasers was necessary to demonstrate many nonlinear effects in the optical frequency range. In 1978, the first high-resolution nonlinear microscope with depth resolution was described by the Oxford group. Sheppard and Kompfner published a study in Applied Optics describing microscopic imaging based on second-harmonic generation. In their report, they further proposed that other nonlinear optical effects, such as two-photon fluorescence, could also be applied. However, the developments in the field of nonlinear optical stalled due to a lack of a suitable laser source. This obstacle was removed with the advent of femtosecond lasers in the 1980s. In 1990, the seminal study of Denk, Strickler, and Webb on two-photon laser scanning fluorescence microscopy was published in Science. Their paper clearly demonstrated the capability of two-photon excitation microscopy for biology, and it served to convince a wide audience of scientists of the potential capability of the technique. Microsc. Res. Tech. 63:3,11, 2004. © 2003 Wiley-Liss, Inc. [source] Intracellular Imaging of HCV RNA and Cellular Lipids by Using Simultaneous Two-Photon Fluorescence and Coherent Anti-Stokes Raman Scattering MicroscopiesCHEMBIOCHEM, Issue 12 2006Xiaolin Nan Hepatitis C virus (HCV) infection is associated with changes in host-cell lipid metabolism. Here we describe a new approach for detecting HCV RNA using two-photon fluorescence (TPF), and HCV-associated changes in cellular lipids using coherent anti-Stokes Raman scattering (CARS) microscopy. By combining the two types of microscopy with a common laser source, we visualized both phenomena simultaneously and profiled cellular lipids and subcellular localization of RNA in real time. [source] | ||||||||||