Table I.
Summary of growth and production characteristics of SEAP-producing CHO cells in different culture conditions
| Culture conditiona | Specific growth rate (h-1) | Max. viable cell conc. (106 cells/mL) | qSEAP (10-6 U/cells/day) | Max. SEAP activityf (U/mL) | Max. volumetric productivity (U/mL/day) | Max. IVCD (106 cells/mL × day) | Culture duration (h)g |
|---|---|---|---|---|---|---|---|
| Suspension | 0.031±0.003 | 1.54±0.10 | 0.045±0.005 | 0.20±0.018 | 0.034±0.003 | 6.22±0.14 | 95 |
| Microcarrier (Cytodex 3) | 0.030±0.001 | 1.31±0.06 | 0.030±0.003 | 0.115±0.014 | 0.017±0.001 | 5.36±0.05 | 130 |
| -3%c | -15% | -33% | -43% | -50% | -14% | ||
| Microcarrier (Cytopore 1)b | 0.027±0.001 | 1.24±0.04 | 0.021±0.002 | 0.106±0.014 | 0.013±0.002 | 6.69±0.47 | 130 |
| -13% | -19% | -53% | -48% | -62% | +8% | ||
| Biphasic Suspension | 0.032 | 1.65 | 0.013d | 0.68 | 0.08 | 10.1 | 130 |
| +3% | +7% | 0.105e | +240% | +135% | +62% | ||
| +133% |
a
Values are mean of two independent experiments except biphasic suspension.
b
Data based on total cell density.
c
Percent change compared to suspension culture.
d
Before temperature shift to 33°C.
e
After temperature shift to 33°C.
f
As previously reported (Nam et al., 2007). Current cultures were harvested before maximum activity was reached to reduce activity of proteases and glycosidases.
g
Cultures were harvested at ∼90% viability.