MT4 (6B6) reacts with the 190, 205 and 220 kDa isoforms of the glycoprotein cell-surface antigen, CD45RB. The antigen is expressed primarily on a subset of human B and T lymphocytes, monocytes, macrophages and granulocytes (weak). CD4+, CD45RA- (memory T cells) cells show a differential expression of CD45RB. Bright CD45RB expression correlates with higher proliferation and IFNγ production when compared with dim CD45RB expression. CD45RB expression may be a mechanism for fine-tuning the responsiveness of memory cells in vivo.
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.