KSR medium for hESC

400 mL Knockout DMEM (Invitrogen 10829-018)

100 mL Knockout Serum Replacement (Invitrogen 10828-028)

5 mL nonessential amino acids (10 mM; Invitrogen)

5 mL L-glutamine (200 mM; Invitrogen)

5 mL β-mercaptoethanol (100X; Chemicon)

Immediately before use, add:

4 μL bFGF solution (10 μg/mL) per 10 mL KSR medium.

Filter the medium with a 0.2-μm bottle filter after adding bFGF.