and EGF that prevent differentiation and promote proliferation of many cell types. A growth-factor-reduced Matrigel is also available. Matrigel contains other proteins in small amounts and its exact composition can vary from lot to lot. For this reason, Matrigel may not be appropriate for experiments that require precise knowledge of all proteins and concentrations. Embryonic stem cells Matrigel is also used as an attachment substrate in embryonic stem cell culture. When embryonic stem cells are grown in the absence of feeder cells, extracellular matrix components are needed to maintain the pluripotent, undifferentiated state (self-renewal). One of these matrices that can be used is diluted Matrigel. When used undiluted, Matrigel promotes stem cell growth and differentiation. See also Cultrex Myogel References External links Corning Matrigel Matrix Cultrex BME Cell culture media Extracellular matrix