Answer:
Because in immunoassays, secondary antibodies are used to bind the primary antibody to assist in detection, sorting and purification of target antigens
Step-by-step explanation:
Secondary antibodies are commonly used for the indirect detection of a target to which a specific primary antibody is first bound. It must be unique in term of exhibiting high specificity and sensitivity to both the antibody species as well as the isotype of the primary antibody being used. High quality secondary antibodies are paramount in achieving meaningful results