The SK9 monoclonal antibody specifically recognizes CD1a. CD1a is a ~49 kDa type I transmembrane glycoprotein that associates non-covalently with β2-microglobulin. The CD1a antigen is present on 60% to 90% of thymocytes, some T-cell leukemias and lymphomas, Langerhans cells, and a subset of dendritic cells. The CD1a antibody does not react with peripheral blood T and B lymphocytes, monocytes, normal bone marrow mononuclear cells, or normal tonsillar B and T lymphocytes. The CD1a antigen has structural similarities to MHC class I antigens and plays a role in the presentation of non-peptide antigens.
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.