XRF analyses reveal that capacitation procedures produce changes in magnesium and copper levels in human sperm

Capacitation makes spermatozoa competent to fertilize oocytes and can be induced in vitro before Artificial Reproductive Technology (ART) procedures to select the best quality and motile spermatozoa. The sperm quality is routinely measured under light microscopy. In the present study we tested the possibility of adding quality information by evaluating the content of some light elements and metals by XRF imaging, similarly to what we previously performed for female primordial gametes. With this approach we identified some major differences in elemental concentration between capacitated and not capacitated semen, indicating that Mg and Cu sperm contents are greatly reduced by capacitation, while there is an apparent Na increase.