Hydrocyanine Fluorescent Dyes to Detect Reactive Oxygen Species

Filed in archive Diagnostics, Methodologies and Instrumentation on December 16, 2008

Researchers have developed new fluorescent probes called hydrocyanines that can be used to detect and measure the presence of reactive oxygen species - molecules implicated in a variety of inflammatory diseases, including cancer and atherosclerosis- in living cells, tissue samples and in vivo.

The researchers have created six hydrocyanine dyes to date - hydro-Cy3, hydro-Cy5, hydro-Cy7, hydro-IR-676, hydro-IR-783 and hydro-ICG - but say that there are potentially 40 probes that could be created. The dyes vary in their ability to detect intracellular or extracellular reactive oxygen species and by their emission wavelength - from 560 to 830 nanometers.

Fluorescing at higher wavelengths allows the hydrocyanine dyes to be used for deep tissue imaging in vivo, a capability that dihydroethidium (DHE), the current "gold standard" for imaging reactive oxygen species, does not have. The dyes also have other advantages over DHE.

The details of the hydrocyanine synthesis process and experimental results on the use of these dyes in cells, tissues and mouse models were reported in the December 8 online version of the journal Angewandte Chemie International Edition.

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Image: Confocal fluorescent images of rat aortic smooth muscle cells (a) incubated with hydro-Cy3, (b) treated with angiotensin II and incubated with hydro-Cy3, and (c) incubated with angiotensin II and TEMPOL before adding hydro-Cy3. Credit: Georgia Tech Image, Courtesy of Kousik Kundu