Figure 5: Linear graph of NP cells differentiated from spinal disc stem cells, and serially passaged for expansion. 40 discospheres were plated on a T25 tissue culture flask, coated with laminin, in chondrogenic media and culture conditions. The T25 culture was passage into a T75 culture flask at confluency. The T75 culture was expanded into 3 T75 culture flasks at confluency.