Post-Implantation Amniotic Sac Embryoid (image) Michigan Medicine - University of Michigan Share Print E-Mail Caption The PASE, or post-implantation amniotic sac embryoid, is a structure grown from human pluripotent stem cells that mimics many of the properties of the amniotic sac that forms soon after an embryo implants in the uterus wall. The structures could be used to study infertility. Credit University of Michigan Usage Restrictions Credit University of Michigan Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.