Mice (BALB/c) were immunized
with the synthetic sequence of SARS-CoV-2
Spike DNA on days 0 and 14 by intramuscular immunization followed
by subcutaneous delivery of recombinant RBD protein (Genscript, USA)
on day 28, as described.23 (link),32 (link) One week after the
final immunization, the immune sera from the immunized mice were collected
and evaluated by enzyme-linked immunosorbent assay (ELISA) to detect
the presence of antibodies targeting SARS-CoV-2 Spike. After confirmation,
mouse splenocytes were used to generate hybridomas as described previously.33 (link) Subsequently, positive hybridoma clones were
characterized by an ELISA, and those selected were further subcloned
and expanded. The antibodies were purified from hybridoma supernatants
and used for further studies.