Department of Biomedical Engineering, University of California Irvine, Irvine, California 92697, United States.
Department of Materials Science and Engineering, University of California Irvine, Irvine, California 92697, United States.
Anal Chem. 2022 Oct 18;94(41):14185-14194. doi: 10.1021/acs.analchem.2c02149. Epub 2022 Oct 3.
The excited-state lifetime is an intrinsic property of fluorescent molecules that can be leveraged for multiplexed imaging. An advantage of fluorescence lifetime-based multiplexing is that signals from multiple probes can be gathered simultaneously, whereas traditional spectral fluorescence imaging typically requires multiple images at different excitation and emission wavelengths. Additionally, lifetime and spectra could both be utilized to expand the multiplexing capacity of fluorescence. However, resolving exogenous molecular probes based exclusively on the fluorescence lifetime has been limited by technical challenges in analyzing lifetime data. The phasor approach to lifetime analysis offers a simple, graphical solution that has increasingly been used to assess endogenous cellular autofluorescence to quantify metabolic factors. In this study, we employed the phasor analysis of FLIM to quantitatively resolve three exogenous, antibody-targeted fluorescent probes with similar spectral properties based on lifetime information alone. First, we demonstrated that three biomarkers that were spatially restricted to the cell membrane, cytosol, or nucleus could be accurately distinguished using FLIM and phasor analysis. Next, we successfully resolved and quantified three probes that were all targeted to cell surface biomarkers. Finally, we demonstrated that lifetime-based quantitation accuracy can be improved through intensity matching of various probe-biomarker combinations, which will expand the utility of this technique. Importantly, we reconstructed images for each individual probe, as well as an overlay of all three probes, from a single FLIM image. Our results demonstrate that FLIM and phasor analysis can be leveraged as a powerful tool for simultaneous detection of multiple biomarkers with high sensitivity and accuracy.
荧光寿命是荧光分子的固有特性,可用于多重成像。基于荧光寿命的多重成像的一个优点是可以同时收集来自多个探针的信号,而传统的光谱荧光成像通常需要在不同的激发和发射波长下拍摄多个图像。此外,寿命和光谱都可以用于扩展荧光的多重化能力。然而,仅基于荧光寿命来解析外源性分子探针受到分析寿命数据的技术挑战的限制。相位向量方法提供了一种简单的图形解决方案,越来越多地用于评估内源性细胞自发荧光以量化代谢因素。在这项研究中,我们使用 FLIM 的相位向量分析来仅基于寿命信息定量解析具有相似光谱特性的三种外源性抗体靶向荧光探针。首先,我们证明了可以使用 FLIM 和相位向量分析准确区分空间上局限于细胞膜、细胞质或细胞核的三种生物标志物。接下来,我们成功解析并量化了三种均靶向细胞表面生物标志物的探针。最后,我们证明了通过各种探针-生物标志物组合的强度匹配可以提高基于寿命的定量准确性,这将扩展该技术的应用。重要的是,我们从单个 FLIM 图像重建了每个探针以及所有三个探针的叠加图像。我们的结果表明,FLIM 和相位向量分析可以作为一种强大的工具,用于同时以高灵敏度和准确性检测多种生物标志物。