The invention provides a defined low protein culture medium for maintaining cells in an undifferentiated state, the medium comprising: a basal medium, an organic acid from the tricarboxylic acid cycle, nonessential amino acids, a combination of growth factors selected from the group consisting of FGF-2 protein, an IGF-1 protein or insulin, a Transferrin protein, and a TGF beta 1 protein, wherein the medium is essentially feeder-free, essentially xeno-free, essentially free of beta-mercaptoethanol, and essentially free of animal-derived or human-derived proteins.