1. Antibodies are found in the plasma of the blood and in bodily fluids . 2. Antibodies are used in the laboratory and are used in test kits to determine any sort of diseases. It is also used as a positive control which shows the reaction should occur of the antibody is present .3.ELISA stands for Enzyme linked Immunosorbent assay .4.ELISA assays are used to determine if a particular antibody is present in a patient’s blood sample.