Neurofilaments are the 10nm or intermediate filament proteins found specifically in neurons, and are composed predominantly of three major proteins called NF-L, NF-M and NF-H. NF-M is the middle or medium neurofilament subunit and runs on SDS-PAGE gels in the range 145-170kDa, with some variation in different species. Antibodies to NF-M are useful to identify this protein and identify neurons and their processes in tissue sections and in tissue culture. NF-M can also be useful in studies of neurofilament accumulations seen in many neurological diseases, such as Lou Gehrig's disease or Alzheimer's disease.