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Updated: May 12, 2026

Detection and Enrichment of Rare Antigen-specific B Cells for Analysis of Phenotype and Function
Published on: February 16, 2017
Enhancing antibody detection sensitivity in lateral flow immunoassays using endospores of Bacillus subtilis as signal
Wen-Zhi Lin1, Chin-Mao Hung2, I-Hsien Lin3
1Department and Graduate Institute of Microbiology and Immunology, National Defense Medical Center, Taipei, 11490, Taiwan; Institute of Preventive Medicine, National Defense Medical Center, New Taipei City, 23742, Taiwan; Department of Biology and Anatomy, National Defense Medical Center, Taipei, 11490, Taiwan.
Abstract:
Antibody detection is the critical first step for tracking the spread of many diseases including COVID-19. Lateral flow immunoassay (LFIA) is the most commonly used method for rapid antibody detection because it is easy-to-use and inexpensive. However, LFIA has limited sensitivity when gold nanoparticles (AuNPs) are used as the signals. In this study, the endospores of Bacillus subtilis were used in combination with AuNP in a LFIA to detect antibodies. The endospores serve as a signal amplifier. The detection limit was about 10-8 M for anti-beta galactosidase antibody detection whereas the detection limit of conventional LFIA is about 10-6 M. Furthermore, the proposed methods have no additional user steps compared with the traditional LFIA. This method, therefore, improved the sensitivity 100-fold without compromising any advantages of LFIA. We believe that the proposed method will be useful for detection of antibodies against HIV, Zika virus, SARS-CoV-2, and so on.

