Left: Analysis of GFP fusion protein-transfected HEK293 cells by Immunocytochemistry. GFP expression (green) was detected with mouse antibody to GFP (red, 1:1,000). Blue: Hoechst nuclear stain. The chicken antibody reveals GFP protein expressed only in transfected cells, and as a result these cells appear orange in color. Right: Western blot analysis of GFP expression (green) in transfected HEK293 cells with mouse anti-GFP antibody (1:1,000). Lane 1: molecular weight marker; Lane 2: non-transfected control cells; Lane 3: mCherry-transfected cells; Lane 4: GFP-transfected cells. A strong band at ~27 kDa corresponds to GFP protein detected only in cells transfected with GFP construct. This antibody does not recognize the mCherry protein. The blot was simultaneously probed with a chicken antibody to HSP60 (red, lanes 2-4).