Western blot analysis of CD3/CD20 was performed by loading 25 µg of CEM (lane 1), Jurkat (lane 2) and rat thymus (lane 3) cell lysates onto an SDS polyacrylamide gel. Proteins were transferred to a PVDF membrane and blocked at 4ºC overnight. The membrane was probed with a CD3/CD20 monoclonal antibody (Product # MA5-14433) at a dilution of 1:10 overnight at 4°C, washed in TBST, and probed with an HRP-conjugated secondary antibody for 1 hr at room temperature in the dark. Chemiluminescent detection was performed using Pierce ECL Plus Western Blotting Substrate (Product # 32132). Results show a band at ~19 kDa.