Cu2+ and Cu+ bathocuproine disulfonate complexes promote the oxidation of the ROS-detecting compound dichlorofluorescin (DCFH).
The water-soluble Cu+ chelator bathocuproine disulfonate (BCS) is widely used to quantify Cu+ or detect Cu+ formation in Cu2+-initiated oxidation reactions. The dichlorofluorescin (DCFH) assay is commonly used to monitor free radical reactions, reactive oxygen species (ROS), or reactive nitrogen species (RNS). Upon oxidation the non-fluorescent DCFH is converted into the fluorescent compound dichlorofluorescein (DCF). In the present communication we show that the Cu+ reagent BCS strongly facilitated the oxidation of DCFH in the presence of Cu2+ or Cu+. In contrast, 2,2'-dipyridyl (DP), which is also a Cu+-complexing reagent, but not as well known and therefore not as commonly used as BCS, did not cause any oxidative modification of DCFH in the presence of Cu2+ or Cu+. We therefore recommend that DP should be used instead of BCS to complex Cu+ in reactions which are initiated by Cu2+ and when ROS/RNS are analyzed by the DCFH oxidation assay.
Laggner
Hilde
H
Center of Physiology and Pathophysiology, Department of Medical Chemistry, Medical University Vienna, Waehringerstr. 10, 1090 Vienna, Austria.
Hermann
Marcela
M
Gmeiner
Bernhard M K
BM
Kapiotis
Stylianos
S
D002713:Chlorine / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D005452:Fluoresceins / Q000737:chemistry*; D010084:Oxidation-Reduction; D010618:Phenanthrolines / Q000737:chemistry*; D017382:Reactive Oxygen Species / Q000737:chemistry*
D005452:Fluoresceins; D010618:Phenanthrolines; D017382:Reactive Oxygen Species; D002713:Chlorine; C028559:bathocuproine sulfonate; D003300:Copper