随着生物制药技术的迅猛发展，抗体药物已成为当今生物医药领域中增长最快的治疗类别之一，广泛应用于癌症、自身免疫疾病、感染性疾病等多种适应症的治疗。抗体药物以其高度特异性和靶向性，能有效中和致病因子、调节免疫反应或引发靶向细胞凋亡，为传统治疗手段提供了重要补充。

在抗体药物的开发与生产过程中，确保其纯度、活性和安全性至关重要。抗体的表达产物通常是复杂的生物混合物，可能含有细胞碎片、宿主蛋白、DNA残留以及其他杂质。为了获得高纯度、高质量的抗体，必须经过一系列精细的纯化步骤，其中亲和层析（Affinity Chromatography）作为首选的纯化方法，在工业化生产中被广泛应用。

亲和层析的核心在于其高特异性的结合机制，这一特性来源于所使用的亲和配基（Affinity Ligands）。这些配基通常固定在色谱柱的填料表面，能够与目标抗体的特定结构域形成可逆结合，从而实现选择性捕获抗体。常见的亲和配基主要包括以下几类：

源自金黄色葡萄球菌（Staphylococcus aureus）的细胞壁，是最早被开发用于抗体纯化的天然蛋白之一。Protein A含有多个IgG结合结构域，主要与抗体的Fc段结合，对人类IgG1、IgG2和IgG4具有高亲和力，对IgG3结合较弱。

来自革兰氏阴性菌（Peptostreptococcus magnus），与Protein A不同，Protein L与抗体的κ轻链结合，而不是Fc段。因此，它能结合含有κ轻链的多种类型的抗体（如IgA、IgM、IgG等）。

基于人类抗体可变区重链第3族（VH3 family）序列构建的人工配基，通常为小分子肽或模拟肽结构，能够特异性识别并结合VH3结构域。人类抗体中约 20%~30% 属于VH3家族，因此该配基具有广泛适用性。

尽管亲和配基在抗体纯化过程中发挥了关键作用，但若在最终药物中其残留未被有效去除，将可能对产品质量、安全性与疗效造成严重影响。检测亲和性配基残留的具体原因包括：

为满足抗体药物生产中对亲和配基残留的高标准检测需求，ACROBiosystems百普赛斯旗下品牌resDetect™推出了多个高性能的亲和配基残留检测试剂盒，采用抗体夹心ELISA原理开发，适用于Protein A、Protein L及VH3等不同亲和配基的残留定量检测。通过使用我们的亲和配基残留检测试剂盒，生物制药企业不仅能提高工艺残留控制的效率与精度，还可加速产品开发进程，增强合规性与市场竞争力。

• 高普适性，多种形式Protein A或变体适用

提供4种不同类型的标准品，适用于目前商业化的大部分Protein A及变体亲和层析填料的残留检测。

The minimum detectable concentration of different forms of protein A are 40 pg/mL. The minimum detectable concentration was determined by adding twice standard deviations to the mean optical density value of twenty zero standard replicates and calculating the corresponding concentration.

• 高回收率

Total 53 samples were tested by ACRO and Competitor C kits simultaneously. 45 samples tested by ACRO (Cat. NO. RES-A029) kit fell into the acceptable recovery range (80-120%), and only 11 samples tested by competitor C kit fell into the acceptable recovery range.

• 极低非特异

具备良好的Protein A检测特异性，与竞品相比无非特异性检出。

3 monoclonal antibody samples which not contain Protein A were tested by ACRO and Competitor P kits simultaneously. All 3 testing results tested by ACRO kit were below LOD (blank+2SD, red line), meanwhile, all 3 testing results tested by Competitor P kit were far beyond the LOD (blank+2SD, green line). Those data show there are non-specific binding of Competitor P kit.

• 抗干扰能力强

We have conducted interference effect test about frequently-used buffers, they have excellent buffer compatibility. For specific buffers, it is recommended that you verify recovery to determine the minimum dilution ratio.

• 特异性强，无交叉反应

Host cell protein (HCP 500 ng/mL) and host cell DNA (HCD 0.5 ng/mL) of HEK293, E.coli or CHO systems were added to human IgG1 (Bevacizumab, 1mg/mL) and human IgG4 (Toripalimab, 1mg/mL), respectively, which were higher than the usual quality standard limit. Then high, medium, and low concentrations of Protein L were added, respectively, and the ratio of Protein L recovery in the Protein L added samples without HCP and HCD was added as the specificity verification index. verification index.