Detection of 6-His-tagged Protein by Western Blot. Samples: 200, 100, or 50 ng of E. coli whole cell lysate expressing a multi-tag fusion protein.     Antibodies: Affinity-purified, HRP-conjugated, goat anti-6-His antibody A190-113P used for WB at 0.2 ug/ml (1:5,000).   Detection:  Chemiluminescence with an exposure time of 3 minutes.