Sperm Preparation (Washing)
The process of separation of the sperm found in the semen. The most commonly used method, which was filtered through a layer of fluids of different density, is gradient density separation. A part of deformed sperm is also eliminated. Then filtered sperm pellet is overlaid with culture medium and let most motile spermatozoits swim to the upper layer of the tube in a controlled temperature and pH environment. This method is called density gradient and swim-up method. Rarely, there are other methods which the special filters or chemicals are used.