Detection of TSPAN33 in Human PBMCs by Flow Cytometry. Human peripheral blood mononuclear cells (PBMCs) either (A) untreated or (B) treated overnight with Recombinant Human IL‑4 (Catalog # 204-IL) and Recombinant Human CD40 Ligand/TNFSF5 (Catalog # 6245-CL) were stained with Mouse Anti-Human TSPAN33 Monoclonal Antibody (Catalog # MAB8405) followed by Allophycocyanin-conjugated Anti-Mouse IgG Secondary Antibody (Catalog # F0101B) and Mouse Anti-Human CD19 PE‑conjugated Monoclonal Antibody (Catalog # FAB4867P). Quadrant markers were set based on control antibody staining (Catalog # MAB0041).