Detection of HA-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, rabbit anti-HA antibody 18850P used for WB at 0.04 µg/ml (1:25,000). Detection: Chemiluminescence with an exposure time of 3 seconds.