Figure 1.

Assessment of sperm morphology using aniline blue staining: A) Healthy sperm with perfectly transparent head and extended and regular tail; B) Sperm with curved midpiece abnormalities that remove the head from the tail axis and have low sperm motility; C) Sperm with amorphous (headless) abnormality that is dead and not able to fertilize the egg; D) Sperm with curved tail, cytoplasmic droplet tail and short tail that disrupt sperm motility and decrease cell viability.