Description: The OX8 monoclonal antibody reacts with rat CD8 alpha. CD8 alpha is a member of the immunoglobulin superfamily which heterodimerizes with CD8 beta to form the CD8 antigen expressed on CD4+CD8+, double-positive thymocytes, the majority of MHC class I-restricted peripheral T cells, and on some macrophages. CD8 binds to MHC class I expressed on the surface of antigen-presenting cells during antigen presentation, and participates in T-cell receptor signal transduction through association with the kinase Lck.