The present disclosure provides methods of generating germ layers from stem cells comprising culturing the stem cells in a culture medium having an osmolality less than 340 mOsm/kg. The present disclosure also includes a method to generate different cell lineages from the germ layers as well as to detect them by immunological methods. The present disclosure further provides methods for the generation, isolation, cultivation and propagation of committed progenitor cells and for the production of differentiated cells from the three germ layers. The present disclosure also provides culture media for use in inducing the three germ layers.