ENA-6 Screen
Enzyme-linked immunosorbent assay method for the semi-quantitative determination of specific IgG autoantibodies to SS-A/Ro, SS-B/La, Sm, Sm/RNP, Jo-1 and Scl-70 in human serum.
The AutostatII assay for detection of autoantibodies is a solid phase immunosorbent assay (ELISA) in which the analyte is indicated by a colour reaction of an enzyme and substrate. The AutostatII wells are coated with purified antigens (1).
On adding diluted serum to the wells the antibodies (2) present bind to the antigen. After incubating at room temperature and washing away unbound material, horseradish peroxidase conjugated anti-IgG monoclonal antibody (3) is added, which binds to the immobilised antibodies.
Following further incubation and washing, tetra-methyl benzidine substrate (TMB) (4) is added to each well. The presence of the antigen-antibody-conjugate complex turns the substrate to a dark blue colour. Addition of the stop solution turns the colour to yellow.
The colour intensity is proportional to the amount of autoantibodies present in the original serum sample.