HeLa cells transiently transfected with DYKDDDDK tag fused protein or non-transfected were fixed with 4% paraformaldehyde (PFA) for fifteen minutes, permeabilized with 0.5% Triton X-100 for three minutes, and blocked with 5% FBS for 60 minutes. Then the cells were intracellularly stained with 1:250 (2μg/ml), 1: 1000 (0.5 μg/ml) and 1:2500 diluted (0.2 μg/ml) Alexa Fluor® 594 anti-DYKDDDDK Tag antibody (red). Nuclei were counterstained with DAPI (blue). The image was captured with a 40X objective.