There is currently a lack of biological tools to study the replication cycle and pathogenesis of SARS-CoV-2, the etiological agent of
COVID-19. Repurposing the existing tools, including
antibodies of SARS-CoV, is an effective way to accelerate the development of
therapeutics for
COVID-19. Here, we extensively characterized
antibodies of the SARS-CoV structural
proteins for their cross-reactivity, experimental utility, and neutralization of SARS-CoV-2. We assessed a total of 10
antibodies (six for Spike, two for Membrane, and one for Nucleocapsid and Envelope viral
protein). We evaluated the utility of these
antibodies against SARS-CoV-2 in a variety of assays, including immunofluorescence, ELISA, biolayer interferometry, western blots, and micro-neutralization. Remarkably, a high proportion of the
antibodies we tested showed cross-reactivity, indicating a potentially generalizable theme of cross-reactivity between SARS-CoV and SARS-CoV-2
antibodies. These
antibodies should help facilitate further research into SARS-CoV-2 basic biology. Moreover, our study provides critical information about the propensity of SARS-CoV
antibodies to cross-react with SARS-CoV-2 and highlights its relevance in defining the clinical significance of such
antibodies to improve testing and guide the development of novel
vaccines and
therapeutics.