Hu proteins are RNA-binding proteins involved in diverse biological processes. The individual members Hel-N1(HuB), HuC, and HuD play important roles in neuronal differentiation and plasticity. The expression of these proteins serves as an excellent neuronal marker. These proteins are typically found in the nucleus , but can be transported to the cytoplasm. The current classic monoclonal antibody (16A11) used to identify these proteins only identifies the cytoplasmic fraction. Our new recombinant humanized monoclonal recognizes the major nuclear fraction of HuD/HuC and Hel-N1. This it has the potential to uncover new biological functions and associations.