Center for Biomolecular Science and Engineering, US Naval Research Laboratory, Washington, DC, United States.
Diagnostic and Surveillance Department, Naval Medical Research Command, Silver Spring, MD, United States.
Front Immunol. 2024 Aug 13;15:1446095. doi: 10.3389/fimmu.2024.1446095. eCollection 2024.
Within the past decade, single domain antibodies (sdAbs) have been recognized as unique affinity binding reagents that can be tailored for performance in a variety of immunoassay formats. Luminex MagPlex color-coded magnetic microspheres provide a high-throughput platform that enables multiplexed immunoassays. We developed a MagPlex bead-based assay for the detection of SARS-CoV-2, using sdAbs against SARS-CoV-2 nucleocapsid (N) protein in which we engineered the sdAb capture reagents to orient them on the beads. The oriented sdAbs provided an increase in sensitivity over randomly oriented sdAbs for samples of N diluted in buffer, which also translated into better detection of SARS-CoV-2 in clinical samples. We assessed the specificity of the assay by examining seasonal coronavirus clinical samples. In summary, we provide a proof-of-concept that a bead-based assay using sdAbs to detect SARS-CoV-2 is feasible and future research combining it with other sdAb-coated beads that can detect other viruses may provide a useful diagnostic tool.
在过去的十年中，单域抗体（sdAbs）已被认为是独特的亲和结合试剂，可以针对各种免疫分析形式进行定制，以提高性能。Luminex MagPlex 彩色编码磁性微球提供了高通量平台，可实现多重免疫分析。我们使用针对 SARS-CoV-2 核衣壳（N）蛋白的 sdAb 开发了一种基于 MagPlex 珠的 SARS-CoV-2 检测方法，我们对 sdAb 捕获试剂进行了工程设计，使它们在珠上定向。与随机定向的 sdAb 相比，定向 sdAb 增加了缓冲液中稀释的 N 样本的灵敏度，这也提高了对临床样本中 SARS-CoV-2 的检测效果。我们通过检查季节性冠状病毒临床样本评估了该测定的特异性。总之，我们提供了一个概念验证，即使用 sdAb 检测 SARS-CoV-2 的基于珠的测定是可行的，未来将其与其他可检测其他病毒的 sdAb 包被珠结合的研究可能提供一种有用的诊断工具。
