Vaccine potency assay

LION/repRNA potency was assayed in vitro. Briefly, serial dilutions of LION/repRNA were incubated on a monolayer of BHK cells in a 96-well plate. Twenty-four hours later, cell lysates were added to an ELISA plate coated with anti-SARS-CoV2 Spike (S1 domain) monoclonal antibody (Genetex GTX632604). Following a primary incubation and washes, a polyclonal anti-SARS-CoV2 Spike (full-length S) primary antibody was added (Abcam {"type":"entrez-nucleotide","attrs":{"text":"Ab272504","term_id":"119928685","term_text":"AB272504"}}Ab272504). Following a secondary incubation and washes, a secondary horse radish peroxidase (HRP)-conjugated antibody was used to detect S-specific binding (Genetex GTX213110-01). Following a final incubation, HRP activity was assayed by TMB/HCL detection and absorbance measured by plate reader (EL_X808, Bio-Tek Instruments Inc) at 450nm.