Please answer the question in the picture. 1. What was the endpoint? 2. What was
ID: 3166250 • Letter: P
Question
Please answer the question in the picture.
1. What was the endpoint? 2. What was the antibody titer? QUESTIONS 1. Was the test performed in this exercise a direct or an indirect ELISA test? 2. Why was the control well colorless? 3. What advantage does the ELISA test have over other immunological techniques such as fluorescent anti- body tests or the use of radioactive antibody assays? CRITICAL THINKING 1. Compare and contrast direct and indirect ELISA techniques. 2. Describe how you would determine whether a bacterium isolated from a patient was Salmonella using the ELISA technique with a known Salmonella antiserum. 3. Why would the ELISA technique be valuable for identifying viruses?Explanation / Answer
Ans. 1).Both direct and indirect ELISA are performed in a polystyrene plate, having 96 wells. Both types of ELISA involve binding of antigens directly to the wells of plate. These techniques only differ in the type of antibodies, used for detection. In direct ELISA, we use a single antibody, which is conjugated with a detection enzyme directly. In indirect ELISA, two antibodies are used, one which binds with antigen and on other conjugated with detection enzyme.
2). The control in ELISA plates no color, since no antibody binds with antigen present in control, so no color reaction was developed in control well.
3). ELISA is more accurate than other immunological techniques. It is more specific, low cost, sensitive, and favorable than other assays, such as RIA (radioactive immune assay) and fluorescence antibody techniques.