These tips will help you choose the right primary antibodies and secondary antibodies: 

• Determine the primary antibody details including the host species in which it was produced, its sensitivity, validation, specificity to your target antigen, and compatibility with your immunoassays. 
• Select a host species of the primary antibody that is different from the host species in which your samples were collected. 
• Choose a secondary antibody that will bind to the primary antibody. The secondary antibody that you choose must have been produced in a host species that is different from the host species in which the primary antibody was produced. For example, you will need an anti-mouse secondary antibody for a mouse primary antibody. Both antibodies must be produced in different host species. 
• The secondary antibody that you choose must match the class or subclass of the primary antibody. For example, choose an anti-mouse IgM secondary antibody when using a primary monoclonal antibody from the mouse IgM class. An IgG secondary antibody is a better option if you don’t know the immunoglobulin classes or subclasses of the primary antibody.