Table 1.
Choice of Purification Method for high yields is dependent on the species.
| Sample | Purification method |
Average Conc. (mg/mL)1 |
Mean ELISA Titer2 | Recovery of Ag- specific Igs (%)3 |
Purity of Ig preparation (%)4 |
Stability at 4°C5 |
| Pre-purification | 1.3 × 106 (1.9 × 105) | |||||
| Immune Rabbit | CA-AS | 12.3 | 1.4 × 106 (3.6 × 105) | 100 | > 95% | NT |
| SEP-EASE (PEG) | 10.9 | 1.1 × 106 (9.6 × 104) | 85 | > 95% | NT | |
| Protein A/G | 8.9 | 1.1 × 106 (6.3 × 104) | 84 | > 95% | NT | |
| Protein G | 14.3 | 1.8 × 106 (2.0 × 104) | 100 | > 95% | NT | |
| Malaria-Exposed Human | Pre-purification | 1.1 × 104 (962) | ||||
| CA-AS | 12.3 | 1.2 × 103 (176) | 11* | > 95% | Yes | |
| SEP-EASE (PEG) | 14.5 | 1.6 × 104 (4 × 103) | 100 | > 95% | Yes | |
| Protein A/G | 14.4 | 4.8 × 103 (95) | 44* | >95% | No | |
| Protein G | 19.8 | 6.6 × 103 (2.1 × 103) | 60 | > 95% | No | |
Data expressed as mean (± SEM) of three independent purification experiments.
1Protein concentration was determined by the absorbance of the solution at 280 nm with an extinction coefficient of 13.5 (standard for IgG) for a 1% IgG solution (10 mg/mL)
2Mean ELISA titer for an OD405 = 1, for rabbits tested against MSP1-p42(FVO) plate antigen, for humans tested against MSP1-p42(3D7) plate antigen
3Recovery of Ag-specific Igs is based on Mean ELISA titer.
4Determined by scanning densitometry on Coomassie Blue stained gels
5Samples were stored for 24 weeks at 4°C and then tested by SDS-gelelectrophoresis, NT = not tested
*A statistically significant difference between the methods in the recovery of Ag-specific Ab by ANOVA. The individual groups were isolated with a Tukey's post test (p < 0.025).