Mesothelin IHC
tumor
TUMOR
Mesothelin expression was centrally assessed in all patients by Ventana Medical Systems using a validated IHC assay performed on 3–5-mm-thick sections of formalin-fixed paraffin-embedded (FFPE) tumor tissue. Automated immunostaining was performed using the VENTANA MSLN (SP74) Dx Assay, which is a rabbit monoclonal primary antibody that binds to mesothelin in paraffin-embedded tissue sections. The specific anti-mesothelin staining was visualized using OptiView DAB IHC Detection Kit (760-700 / 0639500001). A second slide was stained with rabbit monoclonal negative control Ig (790-4795 / 06683380001). Mesothelin protein expression was determined using both the percentage of stained viable tumor cells and the staining intensity