Figure 1.

Combined genetic and protein immunization approach for antibody generation to RBD. (A) Time schedule of the immunization plan. Green arrow represents injection of DNA spike FL at day 0 and 14 the orange one represents the RBD-hFc injection at day 7 and 21. (B) In the upper section, an overview of the spike FL protein from the side and top view is provided (RBD in orange); in the lower section, a schematic representation of the main linear domains encoded by the DNA spike FL used for the immunization plan is provided. (C) The Coomassie stain acquisition of the RBD- hFc protein in reduced and non-reduced form is provided. The expected MW 55 KDa (D) ELISA against the RBD-6xHis protein to evaluate the immunized mice immune titer. Values reported are serial dilutions of sera; the results are shown at 405 nm absorbance.