In vitro activation of human sperm induced by amphibian egg extract.

In this paper we characterize a system for the activation of human sperm using cell-free extracts from Xenopus laevis eggs. We characterize the kinetics of sperm activation in terms of morphological and DNA synthetic parameters. We have optimized some of the components which are necessary for chromatin decondensation and present data to demonstrate that the in vitro process is efficient over a wide range of salt concentrations and amounts of supplementary reducing agents.