Avoiding the mouse step

Geron Corp. took a step forward in the production of human embryonic stem (hES) cells, disclosing new technology that would make it possible to grow the cells without using mouse cells. The technique, which allows the propagation of hES cells without the use of mouse embryonic fibroblast (MEF) feeder cells, has implications for the xenobiotic classification of hES production by the FDA.

Researchers at GERN (Menlo Park, Calif.) showed in Nature Biotechnology that hES cells cultured on Matrigel or laminin in MEF-conditioned medium, which does not contain mouse cells, were maintained in an undifferentiated state for 130 doublings with a normal karyotype, stable proliferation rate, high telomerase activity and continued expression of hES cell surface markers...