Western blot analysis of extracts of HeLa cells, using Phospho-MEK1-pS221 antibody (TA378245) at 1:1000 dilution.HeLa cells were treated by PMA/TPA (200 nM) at 37‚ÑÉ for 30 minutes after serum-starvation overnight. Secondary antibody: HRP Goat Anti-Rabbit IgG (H+L) at 1:10000 dilution. Lysates/proteins: 25ug per lane. Blocking buffer: 3% nonfat dry milk in TBST. Detection: ECL Enhanced Kit. Exposure time: 60s.