Figure 1a: Two-dimensional difference gel electrophoresis image of human normal Astrocyte cell lysate. Lysate was denatured in buffer and solubilized in Tris-HCl, pH 8.8. Gel loading was standardized by total protein (Lowry method). Samples were labeled with cy3/cy5 dye and protein separated using IEF followed by SDS-PAGE. Color image was converted to black and white to analyze volume ratio of cancer/normal samples (n=3). Based on this analysis, candidate protein spots differing notably between GBM and Astrocyte cells were selected for further analysis.