Latex Microsphere-Based Bicolor Immunochromatography for Qualitative Detection of Neutralizing Antibody against SARS-CoV-2

• Published in: Biosensors (Basel) Vol. 12; no. 2; p. 103
• Main Authors: Liang, Zhanwei, Peng, Tao, Jiao, Xueshima, Zhao, Yang, Xie, Jie, Jiang, You, Meng, Bo, Fang, Xiang, Yu, Xiaoping, Dai, Xinhua
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 07-02-2022; MDPI
• Subjects: ACE2; Angiotensin; Angiotensin-converting enzyme 2; Antibodies; Antibodies, Neutralizing - isolation & purification; Antibodies, Viral - isolation & purification; Chromatography, Affinity; Communication; Coronaviruses; COVID-19; COVID-19 - diagnosis; Enzymes; Humans; Immune system; Immunoassay; Infections; lateral flow immunoassay; Latex; latex microspheres; Microspheres; Neutralizing; neutralizing antibody; Peptidyl-dipeptidase A; Point of care testing; Polyethylene glycol; Proteins; receptor binding domain; SARS-CoV-2; Severe acute respiratory syndrome coronavirus 2; Spike Glycoprotein, Coronavirus - immunology; Spike protein; Vaccination; Vaccines; United States > US; China; receptor binding domain; latex microspheres; neutralizing antibody; SARS-CoV-2; lateral flow immunoassay
• ISSN: 2079-6374; 2079-6374
• DOI: 10.3390/bios12020103

Neutralizing antibody (NAb) is a family of antibodies with special functions, which afford a degree of protection against infection and/or reduce the risk of clinically severe infection. Receptor binding domain (RBD) in the spike protein of SARS-CoV-2, a portion of the S1 subunit, can stimulate the immune system to produce NAb after infection and vaccination. The detection of NAb against SARS-CoV-2 is a simple and direct approach for evaluating a vaccine's effectiveness. In this study, a direct, rapid, and point-of-care bicolor lateral flow immunoassay (LFIA) was developed for NAb against SARS-CoV-2 detection without sample pretreatment, and which was based on the principle of NAb-mediated blockage of the interaction between RBD and angiotensin-converting enzyme 2. In the bicolor LFIA, red and blue latex microspheres (LMs) were used to locate the test and control lines, leading to avoidance of erroneous interpretations of one-colored line results. Under the optimal conditions, NAb against SARS-CoV-2 detection carried out using the bicolor LFIA could be completed within 9 min, and the visible limit of detection was about 48 ng/mL. Thirteen serum samples were analyzed, and the results showed that the NAb levels in three positive serum samples were equal to, or higher than, 736 ng/mL. The LM-based bicolor LFIA allows one-step, rapid, convenient, inexpensive, and user-friendly determination of NAb against SARS-CoV-2 in serum.