Description: The HIS47 monoclonal antibody reacts with rat CD5, a 67 kDa surface protein expressed by a majority of thymocytes and mature T cells. While mouse and human CD5 is also expressed on a small subset of B cells called B-1 cells, such CD5+ B cell subset has not been identified in the rat so far. CD5 is a counter-receptor for CD72 and plays a role in the T-B cell interaction.