Bull sperm fertilizing a bovine oocyte. MitoTracker Green FM and DAPI.
Bull sperm prelabeled with MitoTracker Green FM (M7514) and used for in vitro fertilization of bovine oocytes. After fertilization, eggs with bound or incorporated sperm were fixed in 2% formaldehyde, made permeable with Triton X-100 and labeled with an anti-tubulin antibody followed by a tetramethylrhodamine-labeled secondary antibody and counterstained with DAPI (D1306, D3571, D21490). Image contributed by Peter Sutovsky, University of Wisconsin.