MabSelect™ mild elution protein A resin

It is designed to allow antibodies to elute at elevated pH (~pH 5) to avoid acid-induced aggregation, improving yield and process economy in the capture step.

Traditional protein A resins typically elute antibodies at pH 3.5–4, whereas MabSelect™ mild elution resin elutes at around pH 5.

• Elution at ~pH 5 reduces acid-induced aggregation and yield loss.
• Suitable for commercial-scale production, with good alkaline stability, high DBC, and regulatory support file.
• Specific Fc domain interaction enables removal of product-related impurities from asymmetric bispecific antibodies.

Antibodies sensitive to low pH, such as bsAbs with an Fc domain, IgG4, and Fc fusion proteins.

Highly cross-linked agarose matrix with an alkaline-stable protein A–derived ligand (E. coli).

~60 μm.

>60 mg/mL resin at 6 min RT; >55 mg/mL resin at 4 min RT.

300 cm/h (20 cm bed height), 550 cm/h (10 cm bed height).

(In an AxiChrom™ 300 column with 30 cm i.d. packed according to verified methods, when operated in an aqueous solution with a viscosity of 1 cP at 20°C.)

pH 3 to 12 (operational), pH 2 to 13.4 for CIP.

In tests, <1% aggregates, 95 ppm HCP, and 8.3 ppm leached ligand.

No, only full-size mAbs with Fc domains bind; Fab fragments pass through.

IgG1: ~4.99, IgG2: ~5.25, IgG4: ~4.8.

Yes, an elution pH that is too high can lead to larger pool volumes and decreased yield; optimization is essential.

The DBC of MabSelect™ mild elution resin is slightly lower than that of MabSelect PrismA™ resin (60 g/L vs. 72 g/L at 6 min RT). However, for pH-sensitive antibodies higher elution pH may be more important than DBC, making MabSelect™ mild elution more suitable.

After 200 CIP cycles with 0.25 M NaOH, ~80% DBC remained; after 100 purification cycles, ~82% DBC remained with stable yield and low impurities. The resin can also be used with 0.5 M for 100 cycles with 80% remaining DBC.

Yes, specific Fc region interaction enables removal of product-related impurities from asymmetric bispecific antibodies (bsAbs) with protein A binding knocked out on one Fc region.

Bulk resin (25 mL to 10 L), HiTrap™ columns (1 and 5 mL), HiScreen™ columns, and ReadyToProcess™ columns.

Using immunoassay techniques such as Gyrolab with anti-protein A antibodies.

Use low sample load (5–10 mg/mL resin) with a gradient elution from pH 7.0 to 3.4, then step elution at the determined pH.

In 20% ethanol at 2–8°C; equilibrate with buffer containing 20% ethanol or 2% benzyl alcohol to prevent microbial growth.