In this protocol, we describe the direct cytoplasmic microinjection of cytochrome c protein into fibroblasts and primary sympathetic neurons. This technique allows for the introduction of cytochrome c protein into the cytoplasm of cells and mimics the release of cytochrome c from mitochondria, which occurs during apoptosis.
Kole, A. J., Knight, E. R., Deshmukh, M. Activation of Apoptosis by Cytoplasmic Microinjection of Cytochrome c. J. Vis. Exp. (52), e2773, doi:10.3791/2773 (2011).