G Biosciences' Immunotag™ CD21 (ABT-CD21) mouse mAb is a Mouse monoclonal antibody. The Immunotag™ CD21 (ABT-CD21) mouse mAb Antibody was generated using Cr2 as the antigen. It reacts with Human. This antibody has been shown to work in applications such as: Immunohistochemistry, and Immunohistochemistry - fixed.