Alkaline Tolerance: Remaining Binding Activity

Binding

Remain Binding Activity

%

Surface Plasmon Resonance (SPR)

None

None

None

350 nM

None

None

Protein A variants were diluted with 4 M NaOH to a final concentration of 0.5 M NaOH. After alkaline exposure for 2 or 24 h, the solutions were neutralized with 4 M sodium acetate. 10000 RU of human Fc were immobilized on a sensor chip CM5. The neutralized protein A solutions were diluted with HBS-T to a concentration of 350 nM. Alkaline tolerance was represented as the remaining binding activity (%), which was calculated by dividing the effective concentration of an alkaline-treated sample by that of an untreated sample.