Open AccessDevelopment and evaluation of time‐resolved fluorescent immunochromatographic assay for quantitative detection of SARS‐CoV ‐2 spike antigen
Author(s) -
Xu Buzhou,
Tang Hao,
Weng Yiming,
Jones Valerie Sloane,
Luo Shuhong,
Cho Chih Yun,
Lin Yongping,
Fang Jianmin,
Song Xuedong,
Huang RuoPan
Publication year - 2022
Publication title -
journal of clinical laboratory analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.536
H-Index - 50
eISSN - 1098-2825
pISSN - 0887-8013
DOI - 10.1002/jcla.24513
Subject(s) - antigen , covid-19 , point of care testing , fluorescence , real time polymerase chain reaction , reproducibility , chemistry , virology , bradford protein assay , coronavirus , microbiology and biotechnology , chromatography , medicine , biology , immunology , pathology , biochemistry , gene , physics , disease , quantum mechanics , infectious disease (medical specialty)
Abstract Background The spread of COVID‐19 worldwide caused by the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) has necessitated efficient, sensitive diagnostic methods to identify infected people. We report on the development of a rapid 15‐minute time‐resolved fluorescent (TRF) lateral flow immunochromatographic assay for the quantitative detection of the SARS‐CoV‐2 spike protein receptor‐binding domain (S1‐RBD). Objectives Our objective was to develop an efficient method of detecting SARS‐CoV‐2 within 15 min of sample collection. Methods We constructed and evaluated a portable, disposable lateral flow device, which detected the S1‐RBD protein directly in nasopharyngeal swab samples. The device emits a fluorescent signal in the presence of S1‐RBD, which can be captured by an automated TRF instrument. Results The TRF lateral flow assay signal was linear from 0 to 20 ng/ml and demonstrated high accuracy and reproducibility. When evaluated with clinical nasopharyngeal swabs, the assay was performed at >80% sensitivity, >84% specificity, and > 82% accuracy for detection of the S1‐RBD antigen. Conclusion The new S1‐RBD antigen test is a rapid (15 min), sensitive, and specific assay that requires minimal sample preparation. Critically, the assay correlated closely with PCR‐based methodology in nasopharyngeal swab samples, showing that the detected S1‐RBD antigen levels correlate with SARS‐CoV‐2 virus load. Therefore, the new TRF lateral flow test for S1‐RBD has potential application in point‐of‐care settings.