Visualization of heat propagation in biological tissues with two-photon fluorescence microscopy
Journal
Progress in Biomedical Optics and Imaging - Proceedings of SPIE
Journal Volume
7903
Date Issued
2011
Author(s)
Abstract
In this study, we have demonstrated by using time-lapsed two-photon fluorescence microscopy (2PFM), heat flow in biological tissues can be monitored based on temperature-induced fluorescence change of endogenous molecules. Compared to conventional infrared thermography or other thermal imaging tools, 2PFM provides not only sub-micrometer spatial resolution, but also optical sectioning capability inside tissues. As a proof of principle, 2PFM was used to monitor the fluorescence variation in a leaf of Eucalyptus Robusta Smith, which is placed on a home-made heater. By heating the leaf asymmetrically, significant changes of chlorophyll fluorescence were observed in the temperature range of 30°C to 60°C, leading to the visualization of heat conduction dynamics. From the analysis of temporal variation in fluorescence, 0.5°C thermal resolution was demonstrated and detailed temperature distribution can be quantized. Such a technique will be useful for the characterization of heat-related biophysical mechanisms with high spatial and temperature resolution in a thick tissue.
Type
conference paper