Table 1. Area, volume, and sphericity of primitive erythroid cells at different gestational stages.
| Age (embryonic day) | Area (mm2) | SD (mm2) | Volume (mm3) | SD (mm3) | Sphericity | SD | Count |
|---|---|---|---|---|---|---|---|
| Nucleated cells | |||||||
| 12.5 | 379.2 | 61.3 | 522.1 | 103.1 | 0.831 | 0.078 | 363 |
| 13.5 | 407.7 | 56.6 | 560.3 | 90.1 | 0.810 | 0.076 | 322 |
| 14.5 | 416.9 | 59.5 | 570.7 | 102.3 | 0.801 | 0.074 | 435 |
| 15.5 | 368.4 | 45.8 | 490.0 | 87.8 | 0.815 | 0.065 | 182 |
| 16.5 | 292.3 | 43.7 | 378.1 | 56.1 | 0.869 | 0.064 | 10 |
| 17.5 | 246.8 | 23.9 | 262.2 | 40.6 | 0.802 | 0.055 | 5 |
| Enucleated cells | |||||||
| 12.5 | — | — | — | — | — | — | 0 |
| 13.5 | — | — | — | — | — | — | 0 |
| 14.5 | 357.0 | 83.4 | 415.9 | 118.6 | 0.770 | 0.090 | 27 |
| 15.5 | 345.1 | 56.4 | 410.4 | 87.7 | 0.776 | 0.079 | 147 |
| 16.5 | 285.8 | 42.8 | 312.8 | 61.0 | 0.782 | 0.071 | 325 |
| 17.5 | 269.4 | 32.0 | 273.3 | 46.8 | 0.756 | 0.050 | 198 |
Cells were aspirated into micropipettes until the portion of the cell outside the pipette became spherical. The cell area, volume and sphericity were calculated from measured cell dimensions according to Equations 1–3. The mean, standard deviation and number of cells measured are listed for the different days of gestation (age).