Fig. 2.

Cell cycling status, light scattering, and morphology of SP and NSP subsets. Hoechst subsets were stained with 50 μg/ml propidium iodide to measure DNA content. (a) The proportion of cells in different phases of the cell cycle was estimated by using ModFit analysis. The DNA content vs. SSC (b and c) and forward scatter (FSC) vs. SSC profiles (d and e) of SP (b and d) and NSP (c and e) cells were compared to demonstrate the low G₂/M frequency and homogeneously low intracellular complexity of SP cells vs. NSPs, irrespective of cycling status, consistent with a primitive cell type. Cytospins of SP (f) and NSP (g) stained with Giemsa.