These human embryo-like structures (top) were synthesized from human stem cells; they’ve been stained to illustrate different cell types. Images (bottom) of the “embryoids” in the new device that was invented to make them. Yi Zheng/University of Michigan, Ann Arbor
Scientists have invented a device that can quickly produce large numbers of living entities that resemble very primitive human embryos.
Researchers welcomed the development, described Wednesday in the journal Nature, as an important advance for studying the earliest days of human embryonic development. But it also raises questions about where to draw the line in manufacturing “synthetic” human life.