Monoclonal antibodies undergo various forms of chemical transformation which have been shown to cause loss in efficacy and alteration in pharmacokinetic properties of these molecules. Such modified antibody molecules are known as variants. They also display physical properties such as charge that are different from intact antibody molecules. However, the difference in charge is very subtle and separation based on it is quite challenging. Charge variants are usually separated using ion-exchange column chromatography or isoelectric focusing. In this paper, we report a rapid and scalable method for fractionating monoclonal antibody charge variants, based on the use of cation exchange laterally-fed membrane chromatography (LFMC). Starting with a sample of monoclonal antibody hIgG1-CD4, three well-resolved fractions were obtained using either pH or salt gradient. These fractions were identified as acidic, neutral and basic variants. Each of these fractions contained intact heavy and light chains and so antibody fragmentation had no role in variant generation. The separation was comparable to that using column chromatography but was an order of magnitude faster.

单克隆抗体经历了各种形式的化学转化，这些化学转化已显示出导致这些分子的功效丧失和药代动力学性质的改变。这种修饰的抗体分子被称为变体。它们还显示出与完整抗体分子不同的物理特性，例如电荷。但是，电荷的差异非常微妙，基于此的分离非常具有挑战性。通常使用离子交换柱色谱或等电聚焦分离电荷变体。在本文中，我们报告了基于阳离子交换侧向进样膜色谱（LFMC）的分离单克隆抗体电荷变异体的快速且可扩展的方法。从单克隆抗体hIgG1-CD4的样本开始，使用pH或盐梯度可得到三个分离度良好的馏分。这些馏分被鉴定为酸性，中性和碱性变体。这些部分中的每一个都包含完整的重链和轻链，因此抗体片段化在变异产生中不起作用。分离与使用柱色谱的分离相当，但是快了一个数量级。