Fig. 1.
Measurement of 2° CFC frequencies (expressed as number per 105 MNCs) from a series of BM MNC samples assayed over three ranges of plating densities. Bulk long-term culture assays were inoculated in 24-well plates at (A) 2.5 × 105, 5 × 105, and 7.5 × 105cells per well (n = 4); (B) 3 × 104, 105, and 2.5 × 105 cells per well (n = 7); and (C) 2 × 104, 5 × 104, and 105 cells per well (n = 22). Each point represents the mean 2° CFC frequency from three to six replicate cultures, and lines connect the points performed with the same BM sample. A flat line with zero slope would indicate a linear assay response that is unaffected by the assay plating density.
