Extractable nuclear antigens
Extractable Nuclear Antigens are over 100 different soluble cytoplasmic and nuclear antigens. Autoantibodies to these antigens are associated with particular connective tissue disorders.
The six main antigens used in immunological laboratories for detection are Ro, La, Sm, RNP, Scl-70 and Jo1, which are screened for by Ouchterlony double immuno diffusion techniques and confirmed by immunoblotting.