Department of Electrical Engineering, Kwangwoon University, Seoul 01897, Republic of Korea.
Analyst. 2019 Dec 16;145(1):157-164. doi: 10.1039/c9an01140d.
EVs/exosomes are considered as the next generation of biomarkers, including for liquid biopsies. Consequently, the quantification of EVs/exosomes is crucial for facilitating EV/exosome research and applications. Paper-based enzyme-linked immunosorbent assay (p-ELISA) is a portable diagnostic system with low cost that is simple and easy to use; however, it shows low sensitivity and linearity. In this study, we develop p-ELISA for targeting EVs/exosomes by using streptavidin agarose resin-based immobilization (SARBI). This method reduces assay preparation times, provides strong binding, and retains good sensitivity and linearity. The time required for the total assay, including preparation steps and surface immobilization, was shortened to ∼2 h. We evaluated SARBI p-ELISA systems with/without CD63 capture Ab and then with fetal bovine serum (FBS) and EVs/exosome-depleted fetal bovine serum (dFBS). The results provide evidence supporting the selective capture ability of SARBI p-ELISA. We obtain semiquantitative p-ELISA results using an exosome standard (ES) and human serum (HS), with R2 values of 0.95 and 0.92, respectively.
EVs/exosomes 被认为是下一代生物标志物，包括用于液体活检。因此，EVs/exosomes 的定量对于促进 EV/exosome 的研究和应用至关重要。基于纸的酶联免疫吸附测定 (p-ELISA) 是一种具有成本效益的便携式诊断系统，简单易用；然而，它的灵敏度和线性度较低。在这项研究中，我们通过使用基于链霉亲和素琼脂糖树脂的固定化 (SARBI) 开发了针对 EVs/exosomes 的 p-ELISA。该方法缩短了检测准备时间，提供了强结合，并保持了良好的灵敏度和线性度。总检测所需的时间，包括准备步骤和表面固定化，缩短至约 2 小时。我们评估了具有/不具有 CD63 捕获 Ab 的 SARBI p-ELISA 系统，然后使用胎牛血清 (FBS) 和 EVs/exosome 耗尽胎牛血清 (dFBS)。结果提供了支持 SARBI p-ELISA 选择性捕获能力的证据。我们使用外泌体标准品 (ES) 和人血清 (HS) 获得了半定量的 p-ELISA 结果，R2 值分别为 0.95 和 0.92。
