Support longer-term proliferation compared to MEF feeder cells
Culture a wide variety of cell types including pluripotent ESCs, germ-line derived stem cells (e.g. SPCs and MASCs), and primordial germ cell-derived EGCs
Must be mitotically inactivated prior to addition of stem cells
JK1 feeder cells are used for the maintenance of numerous types of stem cells in their undifferentiated state. The cells must be mitotically inactivated prior to the addition of ES cells, such as treatment with mitomycin C (2-4 hr, 10 µg/mL).