Semen Preparation for IVF
		The preparation of semen for IVF serves to separate the fraction containing highly motile sperms from the ejaculated fluid. Only highly motile sperms are able to fertilize an oocytes. None of the other components of the semen may come into contact with the oocytes. Technique: The ejaculated semen is mixed with a special liquid (cell culture medium) and the mixture centrifuged. The resulting sediment contains only the cellular components of the semen. The supernatant is discarded, and a layer of cell culture medium is carefully poured over the sediment. Highly motile sperms then swim up actively from the sediment into the layer of culture medium ("swim-up" method). About 10,000 sperms are used to fertilize each oocytes.