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A novel fluorescence ratiometric method confirms the low solvent viscosity of the cytoplasm
- Source :
- Biophysical Journal. 65:236-242
- Publication Year :
- 1993
- Publisher :
- Elsevier BV, 1993.
-
Abstract
- Two homologous indocyanine dyes, Cy3.18 and Cy5.18, can be used as a ratio pair for fluorometric determination of solvent viscosity. Succinimidyl ester derivatives of these dyes can be attached to inert carrier macromolecules, such as Ficoll 70, for measurement of intracellular or intravesicular solvent viscosity. When the viscosity of the solvent was varied by various methods, the fluorescence intensity ratio (Cy3/Cy5) in a mixture of Cy3.18-Ficoll 70 (Cy3F70) and Cy5.18-Ficoll 70 (Cy5F70) in solution was found to be solely a function of solvent viscosity and was insensitive to other solvent parameters such as dielectric constant, temperature, and the ability of the solvent to form hydrogen bonds. Most important, it was insensitive to the presence of large macromolecules, such as proteins, which increase the shear viscosity but have little effect on solvent viscosity. Following microinjection into the cytoplasm of living tissue culture cells, no binding of Cy3F70 or Cy5F70 to intracellular components was detected by fluorescence recovery after photobleaching. Fluorescence intensity ratio imaging of Cy3F70 and Cy5F70 in non-motile interphase CV1 and PtK1 cells showed that the solvent viscosity of cytoplasm was not significantly different from water and showed no spatial variation.
- Subjects :
- Cytoplasm
Microinjections
Viscosity
Chemistry
Hydrogen bond
Biophysics
Analytical chemistry
Fluorescence recovery after photobleaching
Photochemistry
Fluorescence
Biophysical Phenomena
Fluorescence spectroscopy
Cell Line
Solvent
Microscopy, Fluorescence
Solvents
Fluorometry
Interphase
Research Article
Fluorescent Dyes
Macromolecule
Subjects
Details
- ISSN :
- 00063495
- Volume :
- 65
- Database :
- OpenAIRE
- Journal :
- Biophysical Journal
- Accession number :
- edsair.doi.dedup.....3e0a45c984fb1c378eca756aafe853a8