Antibodies used included a mouse anti-GFP (green fluorescent protein) primary antibody (Roche Diagnostics, 11814460001); a mouse anti-phosphoglycerate kinase-1 (Pgk-1) antibody (Molecular Probes, A6457); and a sheep anti-mouse IgG horseradish peroxidase-linked secondary antibody (GE Healthcare, NA931). The enhanced chemiluminescence (ECL) prime kit was from GE Healthcare (RPN2236).