Comparison of HER-2 expression levels by well-based RPPA and dot blotting. (A) Dot blotting of HER-2 in breast cancer FFPE tissues. Protein extracted from 10 FFPE breast cancer tissue specimens and subsequently a total of 10 μg protein spotted on nictrocellulose membrane. The membrane was hybridized with HER-2 and GAPDH probes. HER-2 expression signals were only detected in 2+ and 3+ positive samples whereas GAPDH detected in all tested samples. Relative HER-2 expressional signals were calculated the ratio of HER-2/GAPDH. (B) Relative HER-2 expressional signals from four different IHC score subgroups were measured using well-based RPPA technology. Gray and white bars represent results of well-based RPPA and dot blotting, respectively. The bar graph shows the average ± SD of three replicated wells. (C) The signals from the well-based RPPA and dot blotting was strongly correlated for HER-2 expression status (R2 = 0.939).