Figure 3. Transmission Electron Microscopy of Cryopreserved Sperm. A and C: Lyophilized in Sperm Freeze Medium: ruptured plasma membrane in head and flagellum, heterogeneous chromatin. Axoneme degenerated. B and D: Lyophilized in Freeze Medium: nuclei severed compromised, ruptured plasma membrane in head and flagellum, heterogeneous chromatin. a: axoneme, fl: flagellum, h: head, mp: midpiece, pm: plasma membrane.