HEK 293 cells were transfected with a vector encoding full length spike protein from SARS CoV2 (pink histogram) or left untransfected (blue histogram) and then stained with 1 µg of Anti-SARS CoV2 Spike Protein RBD Recombinant Rabbit Chimera Monoclonal Antibody, Alexa Fluor 488 (Product # 53-6491-82). Viable cells were used for analysis as determined by Fixable Viability Dye eFluor 780 (Product # 65-0865-18).