Mouse embryonic fibroblast


Mouse Embryonic Fibroblasts are a type of fibroblast prepared from mouse embryo. MEFs show a spindle shape when cultured in vitro, a typical feature of fibroblasts.
The MEF is a limited cell line. After several transmission, MEFs will senescence and finally die off. Nevertheless, researchers can use several strategies, like virus infection or repeated transmission to immortalize MEF cells, which can let MEFs grown indefinitely in spite of some changes in characters.
MEFs are widely used in life science researches, especially in stem cell biology.

Preparation and culture

To prepare MEFs, pregnant female mice are needed. After Sacrificing the mouse, researcher should incise the stomach of female mouse and then detach the embryo from the placenta in a biohazard hood. Then the liver and head should be taken out. Finally digest the remains by enzymes to obtain single isolated cells and culture the cells in a tissue culture dishes. MEF cells can be cultured in vitro in DMEM medium with 10% FBS. To transmit MEFs, researches should use trypsin to digest the cells and transmit 1/5 cells digested into a new dish.

Application in biology

In 1962, George Todaro and Howard Green, two researchers in New York University, immortalized MEFs by repeated transmission. These cells developed into a commonly used cell line NIH 3T3.
MEFs treated by mitomycin or gamma rays are widely used as feeder in embryonic stem cell culture because they can mimic the microenvironment in embryo.
In 2006, Shinya Yamanaka reprogrammed MEFs into iPSCs by introducing 4 factors, which is remarkable in the development of stem cell biology.