Table 1. Purities and yields of the intermediates and the final product obtained by developed downstream processing protocol.
| PROCESSING STEP | PRODUCT | IgG / F(ab')2 PURITY [%] | IgG / F(ab')2 YIELD [%]* | OVERALL IgG / F(ab')2 YIELD [%]** |
|---|---|---|---|---|
| Plasma | 47.8 ± 1.6 (n = 41) | n.a. | n.a. | |
| Heat denaturation | Thermally treated plasma | 46.9 ± 3.0 (n = 9) | 91.6 ± 2.4 (n = 8) | 91.6 ± 2.4 (n = 8) |
| Caprylic acid precipitation | Crude IgG | 81.3 ± 2.2 (n = 6) | 97.3 ± 0.7 (n = 6) | 89.6 ± 3.6 (n = 8) |
| Diafiltration | Pure IgG | 89.0 ± 1.4 (n = 5) | 102.3 ± 3.75 (n = 8) | 91.5 ± 2.0 (n = 7) |
| Pepsin digestion | Crude F(ab')2 | 56.3 ± 6.4 (n = 7) | 92.0 ± 11.3 (n = 7) | 84.1 ± 10.5 (n = 7) |
| Diafiltration | Pure F(ab')2 | 100.3 ± 5.2 (n = 7) | 92.6 ± 6.9 (n = 8) | 78.6 ± 3.0 (n = 6) |
| Anion-exchange HPLC | Ultrapure F(ab')2 | 100.0 ± 2.8 (n = 6) | 100.0 ± 2.5 (n = 23) | 77.0 ± 2.3 (n = 6) |
Purity and yield were calculated according to ELISA. Results are given as mean +/- 95% CI.
* Yield of each processing step obtained during optimisation of refinement strategy.
** Overall yield obtained by developed manufacturing protocol that was independently performed several times on two plasma pools by two analysts.