The 515 monoclonal antibody specifically binds to CD44. CD44 is an 80-95 kDa type I transmembrane glycoprotein, also known as Phagocytic glycoprotein-1 (Pgp-1), or Extracellular matrix receptor type III (ECMR-III). CD44 is a member of the hyaladherin family of hyaluronan-binding proteins, with structural similarities to selectins. CD44 is the receptor for hyaluronic acid. CD44 is expressed on leucocytes, erythrocytes, epithelial cells and weakly on platelets. CD44 has functional roles in cell migration, lymphocyte homing and adhesion during hematopoiesis and lymphocyte activation. The 515 monoclonal antibody can reportedly block cellular adhesion to hyaluronic acid.
The antibody was conjugated to BD Horizon Red 718, which has been developed exclusively for BD Biosciences as a better alternative to Alexa Fluor® 700. BD Horizon Red 718 can be excited by the red laser (628 – 640 nm) and, with an Em Max around 718 nm, it can be detected using a 730/45 nm filter. Due to similar excitation and emission properties, we do not recommend using R718 in combination with APC-R700 or Alexa Fluor® 700.