In the andrology laboratory, there are currently two widely used methods to prepare the semen sample. Both methods aim to isolate the sperm with the best motility and morphology.
The swim-up method takes advantage of the natural ability of sperm to swim, collecting those that have managed to swim to the top.
On the other hand, the density gradient method uses centrifugation force to separate the most functional sperm, using layers with different densities.
Read the full article on: Semen preparation: science debunks a false belief about success ( 62).
By Silvia Azaña Gutiérrez B.Sc., M.Sc. (embryologist).
Last Update: 05/05/2026
