DETERMINING THE LABORATORY-REACTOR SIZE NEEDED FOR SEEDING A BIOLOGICAL REACTION

SIZING OF BIO-REACTOR EXAMPLE AND TUTORIALS

Assuming a minimum 12% inoculum volume, what size of laboratory vessel would be required to initiate the seeding of a 20,000-L full-scale cell-culture bioreactor?

Calculation Procedure

1. Determine the size of reactor that would be required to seed the 20,000-L bioreactor. Since the seed volume must represent 12% of the vessel before reaction starts, the bioreactor being specified in this step would have to have a size 12% that of the 20,000-L bioreactor, or (0.12)(20,000), or 2400 L.

2. Determine the size of bioreactor needed to seed the 2400-L bioreactor of Step 1. Applying the same logic as in step 1, we see that the bioreactor being sought in this second step must be sized at 12% of 2400 L, or (0.12)(2400), or 288 L.

3. Repeat Step 2 successively until a bioreactor of reasonable laboratory volume is reached. Twelve percent of 288 L is 34.6 L; then, 12% of 34.6 is 4.15 L; and 12% of 4.15 L is 500 ml. Thus, a 4.15-L laboratory vessel can be used if available.

Otherwise, use a 500-ml vessel. The contents of the 500-ml vessel provide seeding for the 4.15-L vessel; the contents of the latter vessel then seed the 34.6-L bioreactor; the contents of this latter then seed the 288-L bioreactor; and so on.