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 0.125 µg of Anti-SARS CoV2 Spike Protein RBD Recombinant Rabbit Chimera Monoclonal Antibody, Alexa Fluor 647 (Product # 51-6491-82). Viable cells were used for analysis as determined by Fixable Viability Dye eFluor 520 (Product # 65-0867-18).