Institute of Surface Analysis and Chemical Biology, University of Jinan, Jinan, Shandong, 250022, PR China.
University Hospital, University of Jinan, Jinan, Shandong, 250022, PR China.
Anal Chim Acta. 2022 May 22;1208:339830. doi: 10.1016/j.aca.2022.339830. Epub 2022 Apr 13.
Current serological antibody tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) require enzyme or fluorescent labels, and the titer well plates cannot be reused. By immobilizing histidine (His)-tagged SARS-CoV-2 spike (S1) protein onto tris‒nitrilotriacetic acid (tris-NTA) sensor and using the early association phase for mass-transfer-controlled concentration determination, we developed a rapid and regenerable surface plasmon resonance (SPR) method for quantifying anti-SARS-CoV-2 antibody. On a five-channel SPR instrument and with optimized S1 protein immobilization density, each of the four analytical channels is sequentially used for multiple measurements, and all four channels can be simultaneously regenerated once they have reached a threshold value. Coupled with a programmable autosampler, each sensor can be regenerated at least 20 times, enabling uninterrupted assays of more than 800 serum samples. The accuracy and speed of our method compare well with those of the enzyme-linked immunosorbent assay (ELISA), and the detection limit (0.057 μg mL) can easily meet the requirement for screening low antibody levels such as those in convalescent patients. In addition, our method exhibits excellent channel-to-channel (RSD = 1.9%) and sensor-to-sensor (RSD = 2.1%) reproducibility. Obviation of an enzyme label drastically reduced the assay cost, rending our method (<60 cents) much more cost effective than those of commercial ELISA kits ($4.4-11.4). Therefore, our method offers a cost-effective and high-throughput alternative to the existing methods for serological measurements of anti-SARS-CoV-2 antibody levels, holding great promise for rapid screening of clinical samples without elaborate sample pretreatments and special reagents.
目前用于严重急性呼吸综合征冠状病毒 2(SARS-CoV-2)的血清学抗体检测需要酶或荧光标记物,并且不能重复使用滴度平板。通过将组氨酸(His)标记的 SARS-CoV-2 刺突(S1)蛋白固定在三‒亚氨基‒三乙酸(tris-NTA)传感器上,并利用早期缔合相进行质量转移控制浓度测定,我们开发了一种快速且可再生的表面等离子体共振(SPR)方法来定量抗 SARS-CoV-2 抗体。在五通道 SPR 仪器上,并优化 S1 蛋白的固定密度,四个分析通道中的每一个都可以依次进行多次测量,并且所有四个通道都可以在达到阈值后同时进行一次再生。结合可编程自动进样器,每个传感器可以再生至少 20 次,从而可以不间断地检测超过 800 个血清样本。我们的方法的准确性和速度与酶联免疫吸附测定(ELISA)相当,检测限(0.057μg/mL)可以轻松满足筛选低抗体水平(如恢复期患者)的要求。此外,我们的方法表现出出色的通道间(RSD=1.9%)和传感器间(RSD=2.1%)重现性。省略酶标记大大降低了检测成本,使我们的方法(<60 美分)比商业 ELISA 试剂盒($4.4-11.4)更具成本效益。因此,我们的方法为 SARS-CoV-2 抗体水平的血清学测量提供了一种具有成本效益且高通量的替代方法,有望在无需精心样品预处理和特殊试剂的情况下快速筛选临床样本。