Figure 8. Neurospheres contain a greater number of self-renewing cells than spheroids, whose precursors lose their self-renewal capacity over serial passages.

(A) Spheroids and neurospheres were generated from neonatal SVZs and cultured for 7 DIV in 2% O₂, 5% CO₂, 93% N₂, passaged and plated in a 96-well plate. The limiting dilution assay was performed by plating cells at decreasing densities and then scoring the fraction of negative wells. The reciprocal of the natural logarithm (e) was used to measure the frequency of sphere-forming cells in neurospheres (black) and spheroids (gray). (B) Spheroids and neurospheres were dissociated into single cells and re-plated every 7 days to generate subsequent spheres. The percentage of sphere-forming cells to the total cells plated was determined. Representative images of neurospheres and spheroids from primary (B1, B2), secondary (B3, B4) and quaternary (B5, B6) spheres. Data represent the averaged from two independent experiments.