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).
Figure 1: Multipotent adult spermatogonial-derived stem cells (MASCs) cultured on JK1 cells maintain multipotency. (A): Phase-contrast images of MASC colonies on JK1 cells (A inset) and mouse embryonic fibroblasts (original magnification, x100). (B–C): Immunohistochemistry revealed (B) OCT4 and (C) NANOG expression was preserved in MASCs passaged on JK1 cells for more than 2 weeks. (D–I): MASC-derived teratomas expressed markers for all three germ layers by immunofluorescence. (D) CD31, (E) HNF3β, (F) mucin, (G) VE-cadherin, (H) GFAP, and (I) GCNA. Antibody staining is green. Nuclear counterstain is blue.