This product is comprised of an anti-CD22 Fab' fragment (Bectumomab) labeled with Fluoresein. Fluoresein is a fluorescent dye and it's excitation/emission is 490/525 nm.
CD22, or cluster of differentiation-22, is a molecule belonging to the SIGLEC family of lectins. It is found on the surface of mature B cells and to a lesser extent on some immature B cells. Generally speaking, CD22 is a regulatory molecule that prevents the overactivation of the immune system and the development of autoimmune diseases.