Communication: Fluorochemicals show potential as highly surface-active but non-hemolyzing surfactants, an important combination of properties for biomedical applications such as blood substitutes and contrast agents. Hydrocarbon-based surfactants suffer from the disadvantage that as the length of the hydrocarbon chain (and therefore surface activity) increases, cell-destruction (hemolysis) also increases. The fluorinated surfactants, however, exhibit the opposite effect, an increase in chain length and surface activity leading to reduced hemolysis.