CD8A and infection: Although Motobu et al. (2002) developed and validated the use of BrdU incorporation to analyze B cells, CD4 and CD8 T cell proliferation after mitogen stimulation by flow cytometry and showed that this method was comparable to 3H-TdR incorporation assay in chickens, this assay has not yet been applied to study chicken lymphocyte proliferation in vivo or in vitro after infections or vaccination.