The relationship between lysate protein concentration from untreated and PDGF treated NIH/3T3 cells and the absorbance at 450 nm using PathScan® Total S6 Ribosomal Protein Sandwich ELISA Antibody Pair #7203 is shown. NIH/3T3 cells were starved overnight, treated with PDGF for 20 minutes at 37ºC and then lysed.