Description: The monoclonal antibody Rat-401 recognizes mouse and rat nestin, a Class VI intermediate filament protein (>170 kDa) primarily expressed in neuroepithelial stem cells. Upon neural differentiation, expression is down-regulated and within the adult nervous system is limited to progenitor cells in the cortical subventricular zone, the hippocampal dentate gyrus, dorsal root ganglia satellite cells, and a subpopulation of Schwann cells. Nestin expression is also present in other progenitor cell populations such as pancreatic islet, angiogenic endothelial cells, and bone marrow mesenchymal stem cells. Nestin filaments require vimentin and desmin for assembly into heterodimers and polymers. Upon differentiation, Nestin-containing filaments are replaced by cell type specific intermediate filament proteins, such as GFAP.