A protocol for in vivo detection of reactive oxygen species

2’,7’-dichlorofluorescein (H2DCF) and Dihydroethidium (DHE), have been used extensively in tissue culture experiments to evaluate reactive oxygen species (ROS) production. However, it will be more advantageous to be able to detect real time ROS production in live tissues, especially in Drosophila where the extensive genetic tools available make it possible to compare the phenotype of mutant tissue juxtaposed to its wild-type neighbor. Here, we describe a protocol for imaging ROS production in Drosophila using either H2DCF or DHE. We highlight the specific advantage posed by monitoring ROS production in vivo by comparing the phenotype of cells mutant for genes encoding mitochondrial proteins with their wild-type neighbors. We also show from staining of the germarium that this technique is capable of detecting different levels of ROS production among cells within the same tissue. The whole protocol, from dissection to capturing of images by confocal microscopy can be completed within 2 to 3 hours; and it can be adapted for use in virtually any Drosophila tissue.