Multi-Photon Fluorescence Spectroum of Common Nucleic Acid Probes

2000 ◽  
Vol 6 (S2) ◽  
pp. 820-821
Author(s):  
P. C. Cheng ◽  
B. L. Lin ◽  
F. J. Kao ◽  
C. K. Sun ◽  
I. Johnson
Keyword(s):  
Fluorescence Microscopy ◽  
Fluorescent Probes ◽  
Fluorescence Spectra ◽  
Near Infrared ◽  
Single Photon ◽  
Spectral Response ◽  
Two Photon ◽  
Photon Excitation ◽  
Two Photon Fluorescence ◽  
Photon Fluorescence

Fluorescent probes are commonly used in biological fluorescence microscopy for tracking specific structures and sub-cellular compartments, and for indicating cellular ionic conditions. Recent development in multi-photon fluorescence microscopy has greatly expanded the usage of fluorescent probes in biomedical research. Considering its non-linear nature, two-photon excitation may generate very different fluorescence spectral response in the sample when compared with single photon excitation. It is thus necessary to measure the two-photon spectra of various fluorescent probes, so that two-photon fluorescence microscopy may be operated effectively and the images properly interpreted. This report represents the first installment of a continued effort in characterizing the multi-photon fluorescence spectra of commonly used bio-probes.Two-photon fluorescence spectra excited with near infrared at 780nm were obtained with a SpectraPro-500 spectrophotometer (Acton Research) equipped with a TE-cooled PMT and coupled to a Spectra-Physics Tsunami Ti-sapphire laser pumped by a Coherent Verdi solid-state laser operated at 85MHz, l00fs pulse.

Multi-photon Fluorescence Micro-spectroscopy of Plant Tissues

2000 ◽  
Vol 6 (S2) ◽  
pp. 808-809
Author(s):  
F. J. Kao ◽  
B. L. Lin ◽  
P. C. Cheng
Keyword(s):  
Single Photon ◽  
Second Harmonic ◽  
Spectral Response ◽  
Broad Band ◽  
Small Contribution ◽  
Two Photon ◽  
Photon Excitation ◽  
Photon Spectra ◽  
Photon Fluorescence ◽  
Two Photon Excitation

Considering its non-linear nature, two-photon excitation may generate very different spectral response in samples when compared with single photon excitation. It is thus necessary to measure the two-photon spectra of samples, so that the two-photon fluorescence microscopic images can be properly interpreted. Fluorescence spectra obtained from bulk samples may not provide useful information for microscopy. For instance, due to the relatively small contribution to the total fluorescence intensity, a small number of fluorescent particles in a generally fluorescing specimen may escape detection when the spectrum of the specimen as a whole is obtained. Under two-photon excitation, the background noise can be greatly reduced due to the naturally limited excitation volume of focused laser beam. In addition, signals resulted from second harmonic generation (SHG) may be mixed with low level broad-band background autofluorescence which is commonly found in biological specimen. Therefore, measuring fluorescence spectrum from a micro-focused volume is essential for the proper interpretation of multi-photon fluorescence images.

The Response of Maize Protoplasts to High Intensity Illumination in Multi-Photon Fluorescence Microscopy

2000 ◽  
Vol 6 (S2) ◽  
pp. 806-807
Author(s):  
B. L. Lin ◽  
F. J. Kao ◽  
P. C. Cheng ◽  
P. C. Cheng
Keyword(s):  
Fluorescence Microscopy ◽  
Peak Power ◽  
Near Infrared ◽  
Average Power ◽  
High Peak ◽  
Cell Physiology ◽  
High Peak Power ◽  
Two Photon ◽  
Two Photon Fluorescence ◽  
Photon Fluorescence

Multi-photon fluorescence microscopy has been cited for its advantage in increased depth penetration due to low linear absorption coefficient of biological specimen in the near infrared (NIR) range. Using a pulsed laser, it is possible to efficiently excite two-photon fluorescence with a high peak power while keeping the average power low to avoid thermal and photochemical damages to the specimen. Currently, mode-locked Ti-sapphire and Cr-Forsterite lasers that generate sub-picosecond pulses are used as the light source for multi-photon fluorescence microscopy. Because of the need of high peak power for efficiently exciting two-photon fluorescence, the relationship between cell damage and peak power has become an interesting and much debated topic in the application of multi-photon fluorescence microscopy. It is conceivable that at high illumination intensity, non-linear photochemical processes may have impacts on cell physiology and viability in ways much different from low illumination in the linear domain.

Lysosomal targeted NIR photosensitizer for photodynamic therapy and two-photon fluorescent imaging

2021 ◽  
Author(s):  
Ruiyuan Liu ◽  
Yuping Zhou ◽  
Di Zhang ◽  
Genghan He ◽  
Chuang Liu ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Fluorescence Imaging ◽  
Near Infrared ◽  
Fluorescent Imaging ◽  
High Fidelity ◽  
Design And Synthesis ◽  
Two Photon ◽  
Two Photon Fluorescence ◽  
Photon Fluorescence

Design and synthesis of near-infrared (NIR) emissive fluorophore for imaging of organelle and photodynamic therapy has received enormous attention. Hence, NIR emissive fluorophore of high-fidelity lysosome targeting, two-photon fluorescence imaging,...

scholarly journals High-speed label-free two-photon fluorescence microscopy of metabolic transients during neuronal activity

2021 ◽  
Vol 118 (8) ◽  
pp. 081104
Author(s):  
Andrew J. Bower ◽  
Carlos Renteria ◽  
Joanne Li ◽  
Marina Marjanovic ◽  
Ronit Barkalifa ◽  
...  
Keyword(s):  
Fluorescence Microscopy ◽  
Neuronal Activity ◽  
High Speed ◽  
Label Free ◽  
Two Photon ◽  
Metabolic Transients ◽  
Two Photon Fluorescence ◽  
Photon Fluorescence

Steady-state and time-resolved two-photon fluorescence microscopy: a versatile tool for probing cellular environment and function

2007 ◽  
Vol 76 (3) ◽  
pp. C115-C121 ◽  
Author(s):  
Stefan Denicke ◽  
Jan-Eric Ehlers ◽  
Raluca Niesner ◽  
Stefan Quentmeier ◽  
Karl-Heinz Gericke
Keyword(s):  
Steady State ◽  
Fluorescence Microscopy ◽  
Time Resolved ◽  
Two Photon ◽  
Cellular Environment ◽  
Versatile Tool ◽  
And Function ◽  
Two Photon Fluorescence ◽  
Photon Fluorescence
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