Protein A chromatography is generally less effective at removing antibody aggregates under typical conditions. We recently developed a method that can significantly improve Protein A's aggregate removal capability. This method involves adding calcium chloride/polyethylene glycol (PEG) or sodium chloride/PEG combination to wash and elution buffers. Each salt alone showed some resolution-enhancing effect when its concentration reaches a certain level, and this effect was significantly enhanced by the presence of PEG, which itself had no effect on resolution. The synergistic effect of salt and PEG results in almost complete separation of monomer from aggregates. For the particular case used for method development and demonstration, in comparison with the control run the optimized procedure reduces aggregates in elution pool from 20% to 3-4%. This new method, by facilitating aggregate removal at the capture step, improves the overall robustness of downstream process.

中文翻译：

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一种提高蛋白质A色谱的聚集体去除能力的方法。

蛋白A色谱通常在典型条件下去除抗体聚集体的效率较低。我们最近开发了一种可以显着提高蛋白A的聚集体去除能力的方法。该方法涉及向洗涤和洗脱缓冲液中添加氯化钙/聚乙二醇（PEG）或氯化钠/ PEG组合。当每种盐的浓度达到一定水平时，单独的盐都会显示出一定的增强分辨率的作用，而PEG的存在会显着增强这种作用，而PEG本身对分辨率没有影响。盐和PEG的协同作用导致单体与聚集体几乎完全分离。对于用于方法开发和演示的特殊情况，与对照运行相比，优化的程序可将洗脱池中的聚集物从20％减少到3-4％。