What is the basic principle of immunoblot and ELISA for detecting the presence of autoantibodies in a sample?

1. antigens are labelled on a nitrocellulose filter membrane in case of immunoblot and are coated on a 96-well plate in case of ELISA 2. you add your sample that you think contains the autoantibodies. 3. the autoantibody will bind to the antigen. 4. a secondary antibody conjugated with an enzyme is added. 5. substrate is added to visualise the reaction.