The one photon and two photon excitation spectral properties (absorption, emission spectra, singlet lifetime) of a very efficient two photon absorber, dimethyl-pepep, have been measured in solution. The one photon excitation peak lye near 525 nm and the emission falls at 600 nm, where autofluorescence of cells is weak. The value of the singlet-triplet conversion rate, obtained by two-photon excitation fluorescence correlation spectroscopy, has a quadratic dependence on the excitation power and is comparable to that shown by the dye rhodamine. Preliminary results on stained cells from yeast Saccaromices cerevisiae and Paramecium primaurelia show that the dye preferentially stains DNA in the cell. A direct comparison with a DNA stainer, Dapi, is also performed. Some measurements of the dye functionalized to react with lysine and n-terminal residues of protein are presented. Moreover, this dye can be employed in order to follow in detail some cellular processes such as nuclei division. In vitro fluorescence titration of dimethyl-pepep with calf thymus DNA allowed to estimate the values of the dye-DNA association constant versus ionic strength, and an affinity close to that of ethidium bromide is found.

D'Alfonso, L., Chirico, G., Collini, M., Baldini, G., Diaspro, A., Ramoino, P., et al. (2003). New two-photon excitation chromophores for cellular imaging. In T. Wilson (a cura di), Confocal, Multiphoton, And Nonlinear Microscopic Imaging (Conference on Confocal, Multiphoton and Nonlinear Microscopic Imaging, Munich, Germany, Jun 22-23, 2003) (pp. 27-35). SPIE International Society Optical Engineering [10.1117/12.500637].

New two-photon excitation chromophores for cellular imaging

D'ALFONSO, LAURA;CHIRICO, GIUSEPPE;COLLINI, MADDALENA;BALDINI, GIANCARLO;ABBOTTO, ALESSANDRO;BEVERINA, LUCA;PAGANI, GIORGIO ALBERTO
2003

Abstract

The one photon and two photon excitation spectral properties (absorption, emission spectra, singlet lifetime) of a very efficient two photon absorber, dimethyl-pepep, have been measured in solution. The one photon excitation peak lye near 525 nm and the emission falls at 600 nm, where autofluorescence of cells is weak. The value of the singlet-triplet conversion rate, obtained by two-photon excitation fluorescence correlation spectroscopy, has a quadratic dependence on the excitation power and is comparable to that shown by the dye rhodamine. Preliminary results on stained cells from yeast Saccaromices cerevisiae and Paramecium primaurelia show that the dye preferentially stains DNA in the cell. A direct comparison with a DNA stainer, Dapi, is also performed. Some measurements of the dye functionalized to react with lysine and n-terminal residues of protein are presented. Moreover, this dye can be employed in order to follow in detail some cellular processes such as nuclei division. In vitro fluorescence titration of dimethyl-pepep with calf thymus DNA allowed to estimate the values of the dye-DNA association constant versus ionic strength, and an affinity close to that of ethidium bromide is found.
Capitolo o saggio
Fluorescence imaging; Fluorescence lifetime; Two-photon excitation microscopy; Electrical and Electronic Engineering; Condensed Matter Physics
English
Confocal, Multiphoton, And Nonlinear Microscopic Imaging (Conference on Confocal, Multiphoton and Nonlinear Microscopic Imaging, Munich, Germany, Jun 22-23, 2003)
Wilson, T
2003
0-8194-5009-X
5139
SPIE International Society Optical Engineering
27
35
D'Alfonso, L., Chirico, G., Collini, M., Baldini, G., Diaspro, A., Ramoino, P., et al. (2003). New two-photon excitation chromophores for cellular imaging. In T. Wilson (a cura di), Confocal, Multiphoton, And Nonlinear Microscopic Imaging (Conference on Confocal, Multiphoton and Nonlinear Microscopic Imaging, Munich, Germany, Jun 22-23, 2003) (pp. 27-35). SPIE International Society Optical Engineering [10.1117/12.500637].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/128560
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