Description: The TER-119 monoclonal antibody reacts with mouse erythroid cells from early proerythroblast to mature erythrocyte stages. The TER-119 antigen is present in yolk sac, fetal and newborn liver, but is not expressed by cells carrying BFU-E and CFU-E activities. Several erythroleukemia cell lines tested so far are negative for expression of TER-119 antigen even after dimethylsulfoxide stimulation. Biochemical and molecular analysis of the TER-119 antigen indicate that this molecule is associated with the surface glycophorin A, but is not a typical glycophorin.