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Abstract Developing improved fluorescent probes for imaging the endoplasmic reticulum (ER) is necessary for structure‐activity studies of this dynamic organelle. Two coumarin‐based compounds with sulfonamide side groups were synthesized and characterized asER‐targeting probes. Their selectivity to target theERin HeLa andGM07373 mammalian cells was shown with co‐localization experiments using commercially available probes that localize in theER, mitochondria, or lysozymes. The hydrophobicity of the coumarin‐based probes was comparable to known probes that partition into theERmembrane. Their cytotoxicity in mammalian cells was low withIC50 values that range from 205 to 252 μm. The fluorescent quantum yields of the coumarin‐based probes when excited with 400 nm light were 0.60, and they have a much narrower emission spectrum (from 435 to 525 nm in methanol) than that of the only commercially availableERprobe that is exited with 400 nm light (ER‐Tracker™ Blue‐WhiteDPX). Thus, the coumarin‐based probes are more useful for multicolor imaging with yellow and red emitting fluorophores. In addition to the above benefits,ERlabeling was achieved with the coumarin‐based probes in both live cells and fixed cells, revealing their versatility for a wide range of cellular imaging applications.
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Dibenzothiophene Sulfone Derivatives as Plasma Membrane Dyes
Abstract Dibenzothiophene 5,5‐dioxide (DBTOO) derivatives have recently been shown to processes utility as fluorescent cell dyes. In an effort to extend the functionality of DBTOO‐based dyes to include the visualization of cellular membranes, two lipophilic DBTOO were synthesized and their ability to incorporate into the plasma membrane of HeLa cells was examined by fluorescent microscopy. The photophysical properties of the two new DBTOO derivatives were determined and both have good fluorescent quantum yields and a visible blue emission. Due to agreeable wavelengths of excitation and emission, a standard 4′,6‐diamindino‐2‐phenylindole (DAPI) filter set worked well with these dyes. After co‐staining, it was confirmed that both DBTOO dyes localized in the plasma membrane. The quality of the overlap was quantified using Pearson correlation coefficient, which indicated a strong overlap between the DBTOO dyes and the standard plasma membrane dye. The novel dyes also displayed relatively low toxicity to the HeLa cells with IC50between 10 and 100 µm. Thus, this work reports a new use of DBTOO derivatives as fluorescent microscopy stains.
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- Award ID(s):
- 1900417
- PAR ID:
- 10458695
- Publisher / Repository:
- Wiley-Blackwell
- Date Published:
- Journal Name:
- Photochemistry and Photobiology
- Volume:
- 96
- Issue:
- 1
- ISSN:
- 0031-8655
- Page Range / eLocation ID:
- p. 67-73
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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