Table 1

Fluctuation analysis reveals that vHMECs exist before the proliferative arrest

CategoryCell population
18448240RM9
SET 1SET 2SET 1SET 2SET 2SET 2
Replicates (n)261916241523
Bottleneck population size1.0× 1041.0× 1041.3× 1041.0× 103
PDa (mean ± SD)2.7 ± 0.45.1 ± 0.27.0 ± 0.57.9 ± 1.1
No. cells plated (per replicate) for colony formation1.0× 104∼6.5× 1042.0× 105∼3.4× 105∼1.7× 106∼2.4× 105
No. replicates with X colonies
X = 014141120920
X = 11015120
X = 2110110
X = 3100000
X = 4000110
X ≥ 503b01b2b3b
No. colonies per replicate
 Range0–30–150–10–170–100–51
 Mean (m)0.581.630.311.01.73.5
 Variance (V)c0.57150.23129.2125
V/m 0.999.10.73125.536
χ 2 0.497.70.333.655.7103
P d 0.98<0.0010.99<0.001<0.001<0.001
Frequency (f)e5.8× 102.3× 101.6× 102.9× 109.7× 101.1× 10
  • a PDs from bottleneck until growth plateau.

  • b Actual SET 2 colony numbers (≥5): for specimen 184, colony numbers were 5, 8, 15; for specimen 48, colony numbers were 17; for specimen 240, colony numbers were 7, 10; for specimen RM9, colony numbers were 12, 17, 51.

  • c V = SD2.

  • d Ps were calculated using the χ2 test (Microsoft Excel), with degrees of freedom (df) as follows: 184, 4; 48, 3; 240, 3; RM9, 4.

  • e Mean frequency for a whole SET.