Figure 3.

Single-cell-per-well experiments illustrate that NSC colonies grow clonally. At densities of ≤10 cells/μl, NSC colonies also grow from single cells rather than by multicellular aggregation. a, Single-cell-per-well experiments tracked the growth of 3881 individual cells and confirmed that ∼1 in 900 cells was capable of forming a clonal neural colony in serum-free conditions. b, c, e, When equal numbers of RFP and GFP cells from hESC colonies were plated together (n = 4), spheres of one color (b, c) that indicate a clonal origin, only arose at 10 and 5 cells/μl (e). d, e, Some chimeric spheres (d) arose at densities of 20 and 50 cells/μl (e), indicating that these colonies had formed by the aggregation of ≥2 cells. f, A comparison of sphere formation from single cells per well versus 10 cells/μl (3000 cells/well) showed that the frequency of sphere formation of isolated single cells was equivalent to when cells were plated at 10 cells/μl (t₍₄₎ = 1.22, p = 0.32), n = 3. Data are represented as mean ± SEM.