2e5 of Anti-CD19 CAR-293 cells were stained with 100 μL of 1:50 dilution (2 μL stock solution in 100 μL FACS buffer) Biotinylated Monoclonal Anti-FMC63 scFv Antibody, Mouse IgG1 (Cat. No. FM3-BY45) and isotype control respectively, washed and then followed by PE-SA and analyzed with FACS (QC tested).