Investigations on Average Fluorescence Lifetimes for Visualizing Multi-Exponential Decays
Investigations on Average Fluorescence Lifetimes for Visualizing Multi-Exponential Decays
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DOI：
10.3389/fphy.2020.576862
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发表时间：
2020-10-16
影响因子：
3.1
通讯作者：
Li, David Day-Uei
中科院分区：
文献类型：
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作者：
Li, Yahui;Natakorn, Sapermsap;Li, David Day-Uei
强度和幅度加权的平均寿命，以下分别表示为tau(I)和tau(A)，是揭示Forster共振能量转移(FRET)或荧光猝灭行为的有用指标。在这项工作中，我们讨论了tau(I)和tau(A)之间的区别，并提出了几种无模型的寿命确定算法(LDA)，包括用于快速估计tau(I)和tau(A)的质心法、相量法和积分方程法。对于基于模型的LDAS，我们讨论了模型失配问题，结果表明，双指数模型可以很好地逼近服从多指数模型的信号。根据应用要求，给出了使用LDAs的建议。分析中包括了成像系统的仪器响应。我们解释了为什么只使用tau(I)模型进行FRET分析会产生误导；应该同时考虑tau(I)和tau(A)模型。我们还提出用tau(A)/tau(I)作为双光子荧光寿命图像的新指示剂，结果表明tau(A)/tau(I)是可视化多指数衰变的直观工具。
Intensity- and amplitude-weighted average lifetimes, denoted as tau(I) and tau(A) hereafter, are useful indicators for revealing Forster resonance energy transfer (FRET) or fluorescence quenching behaviors. In this work, we discussed the differences between tau(I) and tau(A) and presented several model-free lifetime determination algorithms (LDA), including the center-of-mass, phasor, and integral equation methods for fast tau(I) and tau(A) estimations. For model-based LDAs, we discussed the model-mismatch problems, and the results suggest that a bi-exponential model can well approximate a signal following a multi-exponential model. Depending on the application requirements, suggestions about the LDAs to be used are given. The instrument responses of the imaging systems were included in the analysis. We explained why only using the tau(I) model for FRET analysis can be misleading; both tau(I) and tau(A) models should be considered. We also proposed using tau(A)/tau(I) as a new indicator on two-photon fluorescence lifetime images, and the results show that tau(A)/tau(I) is an intuitive tool for visualizing multi-exponential decays.