Nanoscience and Nanoengineering, South Dakota School of Mines and Technology, 501 East Saint Joseph Street, Rapid City, SD 57701, USA; BioSystems Networks & Translational Research (BioSNTR), 501 East Saint Joseph Street, Rapid City, SD 57701, USA.
Nanoscience and Nanoengineering, South Dakota School of Mines and Technology, 501 East Saint Joseph Street, Rapid City, SD 57701, USA; BioSystems Networks & Translational Research (BioSNTR), 501 East Saint Joseph Street, Rapid City, SD 57701, USA.
J Colloid Interface Sci. 2021 Apr 15;588:101-109. doi: 10.1016/j.jcis.2020.12.068. Epub 2020 Dec 24.
Immunoassays typically must be stored under refrigerated conditions because antibodies, after being immobilized to solid surfaces, tend to lose their recognition capabilities to target antigens under non-refrigerated conditions. This requirement hinders application of immunoassays in resource-limited settings including rural clinics in tropical regions, disaster struck areas, and low-income countries, where refrigeration may not be feasible. In this work, a facile approach based on a reversable zeolitic imidazolate framework-8 (ZIF-8) coating is introduced to stabilize surface-bound antibodies on enzyme-linked immunosorbent assay (ELISA) plates under non-refrigerated conditions. Using a sandwich ELISA for the detection of neutrophil gelatinase-associated lipocalin (NGAL), a urine biomarker for acute kidney injury, as a model system, ZIF-8 is demonstrated to be able to uniformly coat the surface-bound anti-NGAL IgG, and stabilize the dynamic range and detection sensitivity of the assay after storage at an elevated temperature (50 °C) for at least 4 weeks. The stabilization efficacy of the ZIF-8 coating is comparable to the current "gold standard" refrigeration approach, and superior to the commonly used sucrose coating method. This approach will greatly improve the shelf-life and stability of antibody-coated ELISAs and other types of assays which utilize surface-bound antibodies, thus extending biomedical research and medical diagnostics to resource-limited settings.
免疫测定通常必须在冷藏条件下储存，因为抗体在固定到固体表面后，在非冷藏条件下往往会失去对靶抗原的识别能力。这种要求阻碍了免疫测定在资源有限的环境中的应用，包括热带地区的农村诊所、受灾地区和低收入国家，在这些地方可能无法实现冷藏。在这项工作中，介绍了一种基于可逆沸石咪唑酯骨架-8（ZIF-8）涂层的简便方法，用于在非冷藏条件下稳定酶联免疫吸附测定（ELISA）板上表面结合的抗体。使用夹心 ELISA 检测中性粒细胞明胶酶相关脂质运载蛋白（NGAL）作为模型系统，NGAL 是急性肾损伤的尿液生物标志物，结果表明 ZIF-8 能够均匀地涂覆表面结合的抗 NGAL IgG，并在至少 4 周的高温（50°C）下储存后稳定测定的动态范围和检测灵敏度。ZIF-8 涂层的稳定效果可与当前的“金标准”冷藏方法相媲美，优于常用的蔗糖涂层方法。这种方法将大大提高涂有抗体的 ELISA 和其他利用表面结合抗体的测定方法的保质期和稳定性，从而将生物医学研究和医学诊断扩展到资源有限的环境中。
