Abstract: A method is provided for encapsulating sperm in a particle wherein the particle provides for the timed release of the sperm. In particular, the method uses a gel forming polymer to form the particle and a medium for maintaining most of the sperm in a non-capacitated stage while it is encapsulated. Further provided is a method for artificial insemination using the encapsulated sperm wherein the sperm is naturally or artificially capacitated after the artificial insemination. In an embodiment, capsules containing a core of sperm in a semen extender are formed as a mixture having membranes of different thicknesses to provide varying time of sperm release. In another embodiment, the sperm and extender are dispersed throughout solid beads that vary in chemical property and diameter to provide varying time of sperm release. The extender may be free of glucose, xanthine oxidase and H2O2, and contain fructose, fructose-6-phosphate, pyruvate, lactate or mixtures thereof as a carbohydrate source.

Abstract: A method, medical device (10) and test kit for capacitation of sperm for fertilizing eggs in vitro or in vivo, is described. The sperm is particularly from lower mammals, such as domestic animals and wild animals to be bred in captivity. The capacitated sperm is also useful in research relating to the nature of capacitation of sperm following modification of the head of the sperm upon capacitation.