Turcotte Raphaël, Wu Juwell W, Lin Charles P
Wellman Center for Photomedicine and Center for Systems Biology, Massachusetts General Hospital, Harvard Medical School, CPZN 8238, 185 Cambridge Street, Boston, MA 02114, USA.
J Biophotonics. 2017 Feb;10(2):206-210. doi: 10.1002/jbio.201600077. Epub 2016 Jul 19.
Photoconversion, an irreversible shift in a fluorophore emission spectrum after light exposure, is a powerful tool for marking cellular and subcellular compartments and tracking their dynamics in vivo. This paper reports on the photoconversion properties of Di-8-ANEPPS, a commercially available membrane dye. When illuminated with near-infrared femtosecond laser pulses, Di-8-ANEPPS undergoes multiphoton photoconversion as indicated by the supralinear dependence of the conversion rate ρ on the incident power (ρpc∝Iexc2.27), and by the ability to photoconvert a thin optical section in a three-dimensional matrix. The characteristic emission spectrum changed from red to blue, and ratiometric analysis on single cells in vitro revealed a 65-fold increase in the blue to red wavelength ratio after photoconversion. The spectral shift is preserved in vivo for hours, making Di-8-ANEPPS a useful dye for intravital cell marking and tracking applications.
光转换是指荧光团发射光谱在光照后发生的不可逆变化，是标记细胞和亚细胞区室并在体内追踪其动态的有力工具。本文报道了一种市售膜染料Di-8-ANEPPS的光转换特性。当用近红外飞秒激光脉冲照射时，Di-8-ANEPPS会发生多光子光转换，转换速率ρ对入射功率呈超线性依赖（ρpc∝Iexc2.27），并且能够对三维基质中的薄光学切片进行光转换，这表明了该现象。其特征发射光谱从红色变为蓝色，体外对单细胞进行的比率分析显示，光转换后蓝红波长比增加了65倍。这种光谱偏移在体内可保持数小时，使得Di-8-ANEPPS成为用于活体细胞标记和追踪应用的有用染料。
