Identification of specific ANEA by biochemical approaches. (I) Identification of anti-gp210 autoantibodies. Immunoprecipitation (IP) of gp210 and immunoblotting (Blot) using IgG (IgG) and IgM (IgM) secondary antibodies. (II) Identification of autoantibodies directed against lamins A/C (LmA/C) and B (LmB) by immunoblotting (Blot) using purified proteins (SDS-PAGE). (III) Identification of anti-LBR autoantibodies by immunoblotting (Blot) using purified recombinant LBR (SDS-PAGE). "d.p." denotes characteristic proteolytic products of LBR that are produced after expression in bacteria. Sera negative (s33, s201) and highly (s211, s21) or moderately (s196) positive for LBR are shown. (IV) Identification of anti-p62 autoantibodies.