Intravital multiphoton photoconversion with a cell membrane dye

• Published in: Journal of biophotonics Vol. 10; no. 2; pp. 206 - 210
• Main Authors: Turcotte, Raphaël, Wu, Juwell W., Lin, Charles P.
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY‐VCH Verlag 01-02-2017; Wiley Subscription Services, Inc
• Subjects: Animals; Biological activity; Bone marrow; Cell Membrane; cell tracking; Compartments; Conversion; Dyes; Emission analysis; Exposure; Femtosecond; Femtosecond pulses; Fluorescence; Fluorescent dyes; Fluorescent Dyes - chemistry; I.R. radiation; In vitro methods and tests; Infrared lasers; Intravital Microscopy; Lasers; Light; Light effects; Membranes; Mice, Inbred C57BL; multiphoton; Photoconversion; Pyridinium Compounds - chemistry; Spectra; Tracking; two‐photon fluorescence microscopy; Wavelength; two-photon fluorescence microscopy; intravital microscopy; Photoconversion; cell tracking; bone marrow; multiphoton
• ISSN: 1864-063X; 1864-0648
• DOI: 10.1002/jbio.201600077

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 ρpc 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.
The color of the moon can change during a lunar eclipse so can certain fluorescent dyes when light is shone on them. The changes in fluorescence emission spectrum, termed photoconversion, can be highly controlled, thus making this process a useful tool tostudy biological process in vivo at the cellular and subcellular levels. This Letter describes intravital multiphoton photoconversion of Di‐8‐ANEPPS, a membrane dye, in murine bone marrow.