Protein A, Protein L and KappaSelect affinity resins have been widely used for antibody purification. Elution of antibody bound to these resins is typically achieved by acidic pH. In addition, elution can be moderately adjusted by tuning the salt concentration in mobile phase as hydrophobic interactions play a major role in binding. In this study, we assessed the impact of salt concentration in mobile phase on antibody retention in these three types of affinity chromatography. The data suggest that salt concentration has a bigger impact on retention in the two light chain-binding affinity columns (i.e., Protein L and KappaSelect) than in Protein A column. In particular, lowering salt concentration in mobile phase for Protein L and KappaSelect columns allows elution become feasible at higher pH. In addition, this finding suggests that wash in these two types of column aimed at removing weakly-bound byproducts can also be performed at increased pH by lowering salt concentration in the wash buffer. Rendering wash and elution feasible at higher pH has practical value for cases where the target antibodies are sensitive to stringent conditions.

蛋白A，蛋白L和KappaSelect亲和树脂已被广泛用于抗体纯化。通常通过酸性pH来洗脱与这些树脂结合的抗体。此外，可以通过调节流动相中的盐浓度来适当调节洗脱液，因为疏水性相互作用在结合中起主要作用。在这项研究中，我们评估了这三种亲和色谱中流动相中盐浓度对抗体保留的影响。数据表明，盐浓度对两个轻链结合亲和力色谱柱（即Protein L和KappaSelect）的保留影响要大于Protein A色谱柱。特别是，降低蛋白质L和KappaSelect色谱柱流动相中的盐浓度可使洗脱在较高的pH值下变得可行。此外，该发现表明，通过降低洗涤缓冲液中的盐浓度，还可在提高pH的情况下在这两种旨在去除弱结合副产物的色谱柱中进行洗涤。对于目标抗体对严格条件敏感的情况，在较高的pH下进行可行的提纯洗涤和洗脱具有实用价值。