Extractable Nuclear Antigens are soluble cytoplasmic and nuclear components that are antibody targets with over 100 different antigens described. The main 6 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 Immuno blotting. Antibodies to these antigens have particular associations with various connective tissue disorders. On anti-nuclear antibody tests, they have a speckled pattern.