The AL-21 monoclonal antibody specifically binds to a non-polymorphic determinant of Ly-6C, a 14-17 kDa GPI-linked cell-surface antigen found on some monocyte/macrophage populations, granulocytes, endothelial cells, plasma cells, and thymocyte, NK-cell, and T-subsets. Mice with the Ly-6.2 alloantigen (eg, AKR, C57BL, C57BR, C57L, C58, DBA/2, PL, SJL, SWR, 129) have subsets of CD8+ and CD4+ Ly-6C+ T cells, while Ly-6.1 strains (eg, A, BALB/c, CBA, C3H/He, DBA/1, NZB) have only CD8+ Ly-6C+ T cells. Upregulation of Ly-6C expression on CD8+ T cells by interferons α and β and poly (I:C) has been described, and Ly-6C is a memory marker on CD8+ T cells.
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.