Claudio Stern is a developmental biologist who is furthering our understanding of how body pattern is established in the early embryos of vertebrates. Working principally in chick embryos, he has provided important information about the way that cells organise themselves to form more complex structures.

One of his interests is the formation and influence of somites — paired blocks of tissue that form along the head–tail axis during the development of segmented animals. He showed that somites play a role in determining the segmentation of the nervous system. His other achievements include a collaboration with Cliff Tabin, which resulted in the discovery of the first genes that specify differences between the left and right sides of the body.

Claudio is also well known for his studies of gastrulation (formation of the three primary cell layers of the embryo and the origins of the embryonic axis), and for disentangling some of the mechanisms that initiate the development of the nervous system.