HeLa cells non-transfected (A) or transfected with DYKDDDDK Tag fused protein (B and C) were fixed with 4% paraformaldehyde (PFA) for 10 minutes, permeabilized with 0.5% Triton X-100 for 3 minutes, and blocked with 5% FBS for 60 minutes. Then the cells were intracellularly stained overnight at 4 degrees with 1: 250 diluted (2 µg/ml, Figure A and B) and 1: 1000 diluted (0.5 µg/ml) Alexa Fluor® 488 anti- DYKDDDDK Tag (Figure C, green). Nuclei were counterstained with DAPI (blue). The image was captured with a 40X objective.