The addition of extender to<unk>  protects the sperm cells against possible damage by toxic<unk> al plasma, as well as providing nutrients and cooling buffers if the<unk>  is to be cooled.<unk>  also serves to protect sperm from bacteria by adding antibiotics to it to prevent increase of bacteria. In the case of freezing extenders, one or more penetrating cryoprotectants will be added. Typical cryoprotectants include glycerol, DMSO and dimethylformamide. Egg yolk, which has cryoprotective properties, is also a common component.
Semen extender
Penis extender
Cholagogue
Moisturizer
Deodorant
Querulant
Geroprotector
Chemical depilatory