And that sample, for example, could be a blood sample or it could be a urine sample coming from an individual. So one important type of method that, that utilizes these monoclonal and polychlonal antibodies is Eliza. And Eliza is not only used in biochemistry, it is also used in medicine. So Eliza stands for enzyme linked Immunosorbin Assay. And this is a method that utilizes these monoclonal or sometimes polyclonal antibodies to determine and quantify the presence of some type of protein in our sample. Now, we're going to discuss two types of Eliza methods.