Western blot analysis of BRCA1 was performed with 10 µg of HeLa cells transfected with Transfection Reagent alone (Lane 1), 100nM Non-Targeting control siRNA (Lane 2), or 100nM siRNA against BRCA1 (Lane 3). Proteins were resolved using a NuPAGE® Novex 4-12% Bis-Tris Gel (Product # NP0322BOX), XCell SureLock™ Electrophoresis System (Product # EI0002), and a protein size ladder. Proteins were wet transferred to a Pierce Nitrocellulose Membrane (Product # 88025) OR Pierce PVDF Membrane (Product # 88518) and blocked with Pierce Starting Block T20 (PBS) Blocking Buffer (Product # 37539) for 1 hour at room temperature. BRCA1 was detected at ~ 208 kDa using BRCA1 Mouse monoclonal antibody (Product # MA1-16618) diluted in Pierce Starting Block T20 (PBS) Blocking Buffer 4°C overnight on a rocking platform. Pierce Goat Anti-Mouse (Product # 31437) HRP-Conjugated Antibodies at a 1:2500 dilution were used and chemiluminescent detection was performed using Pierce Supersignal West Dura Maximum Sensitivity Substrate (Product # 37071). Relative density of the bands normalized to Lamin A/C (74/65 kDa). BRCA1 Antibody (Product # MA1-16618) confirms silencing of BRCA1 expression.