S
cientists grow and differentiate human embryonic and induced pluripotent stem (iPS) cells in laboratories around the world to study numerous cellular processes and develop regenerative medicines. To faithfully culture generations of these sensitive cells and drive them toward desired cell types, scientists add several components to their media and perform many steps, all while following strict protocols.
To continuously grow precious stem cells in vitro, researchers must preserve their “stemness.” They often accomplish this by using feeder cells, such as mouse or human fibroblasts, that deliver unknown factors that promote stem cell self-renewal. To grow in vitro, feeder cells require animal components such as fetal bovine serum (FBS). These ingredients do not comply with the Standard for Biological Ingredients, which regulates source materials derived from humans or animals. Additionally, feeder cells often carry viruses that infect stem cells. As an alternative, some scientists now use feeder-free cultures to avoid ...
