Evaluation of immunoglobulin purification methods and their impact on quality and yield of antigen-specific antibodies

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).

ISSN: 1475-2875