Frequently Asked Question
Question 1: Write the principle on which ELISA works?
Answer:
It works on the principle that particular antibodies will bind the target antigens and they will detect the absence or presence and quantity of binding antigens. The plate we are using should be coated with antibodies with high affinity to increase the precision and sensitivity of the assay. ELISA can provide a correct and useful measures of antibody-antigen concentration.
Question 2: Briefly discuss Sandwich ELISA.
Answer:
Sandwich ELISA
- It helps to detect antigens in samples.
- Here microtiter well is coated with antibodies.
- Add a sample that contains antigen to the wells and wash it to remove free antigen.
- Now an enzyme-bound secondary antibody that binds to a different epitope on the antigen is added. Wash the wells to remove all free secondary antibodies.
- An enzyme-specific substrate is added to the plate to form a measurable color product.
Question 3: Write disadvantages of ELISA.
Answer:
Disadvantages of ELISA
- Results should be obtained in a short time as the detection is based on substrate/enzyme reaction.
- Information is limited to the presence or amount of antigens.
Question 4: Name the diseases diagnosed by ELISA.
Answer:
Diseases that can be diagnosed through ELISA
- Chickenpox
- Rotavirus
- AIDS
- Lyme diseases
- Pernicious anemia
Question 5: Explain the procedure of ELISA.
Answer:
ELISA is one of the easiest test that can be done quickly and rapidly and it requires any type of sample from the patient. The entire process includes :
- Antibodies bind to polystyrene sheets, which are solid surfaces, and it was attracted towards bacteria, other hormones and antibodies.
- Antigen-coated microtiters are filled with this antigen-antibody mixture and free antibodies are removed by washing.
- A secondary antibody specific to the primary antibody is added, which normally binds to the enzyme.
- Remove free enzyme-bound secondary antibodies by washing the plate.
- Finally, the board is added. The substrate is converted by an enzyme into a colored product that can be measured spectrophotometrically.
What is ELISA? – Introduction, Procedure, Types, Applications
A basic array technique called enzyme-linked immunosorbent assay that basically used to identify and measure the antibodies, proteins, peptides, and hormones in the blood. Its test result can provide us the information about the disease that may help in planning treatment. It compares with other antibody assays to provide quantitative results and separation of non-specific and specific interactions caused by continuous binding to solid surfaces, usually polystyrene multiwell plates.
Antigen (Ag)
A toxic molecule or any foreign matter that causes an immune response in the body is called an antigen. In immunology, an antigen term originally referred to substances that generate antibodies. Antigens can be proteins, peptides, lipids, or nucleic acids.
Antibody (Ab)
An antibody is a blood protein that is produced in our body by the immune system in response to and to counteract a specific antigen. Antibodies are also called immunoglobulins.