Sperm capacitation is the process by which the sperm acquires the ability to fertilize the egg. In the natural process, it occurs after ejaculation, when sperm enter the female reproductive system. In the laboratory we force this capacitation by means of of sperm washing in which, in addition, we select the best ones, eliminating the immotile ones and any substances that could be toxic for the spermatozoid.
In the laboratory, the duration of this process is between 30-60 minutes, depending on the type of capacitation we select. We can choose between:
- Density gradients: where we separate and concentrate by centrifugation. In this technique we select those spermatozoa that manage to cross the gradients. This takes about 30 minutes.
- Swim-up: where we also centrifuge the sample to concentrate it and eliminate the supernatant (seminal plasma). We then add a new medium and it will be in this new medium where we will select the spermatozoa that have managed to rise or "swim" after 40 minutes in the incubator.
Read the full article on: What is sperm cell capacitation? – definition and the in vitro techniques ( 61).
Leonor Ortega López
Leonor Ortega López studied Biological Sciences at the University of Valencia (Spain). She then completed a Master's Degree in Human Reproduction taught by the Spanish Fertility Society and the Complutense University of Madrid.