Immunostaining Using an Antibody against Active Caspase-3 to Detect Apoptotic Cells in Drosophila

The activation of mammalian caspase-3 after proteolytic cleavage adjacent to residue Asp175 produces a large (17/19-kDa), active subunit. A commercially available antibody recognizes the large, active subunit of caspase-3 but not the full-length inactive caspase-3. This antibody has also been shown to detect active Drosophila effector caspases. Here, we present a protocol showing how this antibody can be used to detect apoptotic cells in various Drosophila tissues and developmental stages and discuss the specificity of the antibody.