Colossal Biosciences built a 3D-printed artificial egg that lets chicken embryos develop normally outside the shell. Researchers transfer egg contents within a day or two of laying, and chicks hatch without issues. The device maintains the membrane tension the yolk provides and uses an oxygen-permeable lining so embryos develop in normal atmosphere with just humidity control.

Only calcium supplementation is needed since the embryo normally extracts it from the shell. This solves a long-standing problem in developmental biology—being able to continuously image live embryos rather than stopping at two time points. Researchers have long chipped holes in chicken eggs to manipulate embryos, but tracking dynamic processes like cell movement has been difficult.

Colossal's container lets them film development continuously, tracking how cells move and tissues reorganize. For the company's de-extinction projects targeting the dodo and moa, the technology addresses a different challenge: these birds are far larger than any existing species, so there's no natural egg that can host them. Colossal says it will give the technology away for research use.