SARS-CoV-2 Proteins Microarray by Photoimmobilization for Serodiagnosis of the Antibodies

Abstract

An automated microarray diagnostic system for SARS-CoV-2 protein-specific antibodies was developed using photoimmobilized viral proteins. Photoimmobilization strategy was used to immobilize proteins by crosslinking reactions of photoreactive polymers. Aqueous solutions of proteins were spotted on a polymer-coated plate and dried in air. Then, the proteins were immobilized via irradiation with an ultraviolet lamp. Virus-specific IgG and IgM in the serum were automatically assayed using the microarray plate. After the serum was added on the microarray plate, peroxidase-conjugated anti-human-IgG or -IgM antibody was added, and the chemical luminescence intensity was detected using a sensitive charge-coupled device camera. The developed microarray assay showed higher sensitivity than the conventional immune chromatography. Additionally, compared with conventional microarray using nitrocellulose slide, the developed microarray format was useful for rapid assay formats in serodiagnosis of viral infectious diseases and assessment of immune status for clinical applications.

Rapid and quantitative detection of multiple antibodies against SARS-CoV-2 mutant proteins by photo-immobilized microarray

“…Tween 20 (Sigma-Aldrich, St. Louis, MO, USA) and 2-amino-2-hydroxymethyl-propane-1,3-diol (Tris)-buffered saline (Takara Bio, Shiga, Japan) were mixed in water to obtain a buffer solution (TBST). Rabbit anti-SARS-CoV-2 antibodies used for control experiments were the same as previously reported [ 27 ]. Rabbit anti-nucleocapsid antibodies and anti-spike/RBD antibodies were diluted to 5000 and 500 times, respectively, while anti-rabbit IgG antibodies were diluted 12,000 fold.…”

“…Normal human IgG was purchased from FUJIFILM Wako Pure Chemical (Osaka, Japan). Horseradish peroxidase (HRP)-conjugated goat anti-human IgG was also the same as previously reported [ 27 ]. For human sera and whole-blood measurements, 3000- and 12,000-time dilutions of anti-human IgG antibodies were used to conduct the microarray assay for 8 and 30 min, respectively.…”

“…It is available as part of health insurance coverage in Japan. We partially extended DropScreen for detecting antibodies against SARS-CoV-2 proteins [ 27 ]. The photoimmobilization methods can covalently immobilize various organic substances without any specific functional groups and with random orientation of antigens to expose various sites of immobilized antigens for interactions with polyclonal antibodies.…”

“…We previously reported a photo-immobilized microarray assay for SARS-CoV-2 antibodies [ 27 ]. Here, we use the photoimmobilization method employing two types of photoreactive polymers for quantitative and rapid detection of IgG against SARS-CoV-2 proteins of mutants using blood directly sampled from the fingertip.…”

Biomimetic and Biological Nanoarchitectonics

“…For further development of bio-functional systems, conjugation of bioactive components onto artificial devices and nanostructured materials is necessary [ 171 , 172 ]. One of the popular strategies in bio-device conjugation nanoarchitectonics is rational immobilization of bioactive components such as enzymes onto electrodes.…”