Cell Signaling Technology's CD21/CR2 (2G9) Mouse mAb is a Mouse monoclonal antibody. The CD21/CR2 (2G9) Mouse mAb Antibody was generated using Cr2 as the antigen. It reacts with Homo Sapiens, and Human. This antibody has been shown to work in applications such as: Immunohistochemistry, and Immunohistochemistry - fixed.