What are the different types of ELISA test methods?
The ELISA or enzyme-linked immunosorbent assay is known to be a plate-based one that helps detect and measure the quantity of antibodies, proteins, hormones and others. The other name of ELISA is EIA and ELISA has used in the field of biotechnology, medicines and the like as a useful diagnostic tool. To identity target object, different antibodies and change in color are used. For antigen and antibody concentration, ELISA is a suitable kit to use.
What does ELISA test mean?
ELISA or EIA is a type of test with which it is possible to detect the presence of antibodies in the human body. The test is conducted to diagnose health problems like the following.
- Rotavirus
- Syphilis
- Lyme disease
- HIV caused by AIDS
- Toxoplasmosis
- Pernicious anaemia
- Zika virus
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Using an IFNG ELISA Kit, an antigen is immobilized, and then it is mixed with an antibody that works as an enzyme. Therefore, ELISA is often used as an excellent screening tool before conducting other tests.
Five-step procedure of ELISA
The IFNG ELISA Kit is used to measure the quantity of antibody concentration in the human body.
- First, you have to coat microtiter plate with antigen
- Try to block unbound sites to prevent positive results
- Add antibody to wells
- Try to add secondary antibody with an enzyme
- Here, a substrate reacts with an enzyme-producing colored product that indicates a positive reaction.
The color change is properly visible in an ELISA kit, making it suitable to understand the presence of antigen in the body. Two results are derived from this test. It can help detect the presence of antigen that an antibody recognizes or it is used to test antibodies that an antigen recognizes.
How the direct method of ELISA works?
In the direct method, a sample containing antigen is used to coat microwell plates. The labeled antigen binds quickly and therefore, it can be said that the ELISA method is an advantageous one. It helps to keep away from the problems of cross-reaction with other antibody in other components of samples. However, the direct ELISA method is better than every other antibody test that is time-consuming and costly.
Indirect ELISA method
The indirect method consists of two steps by using a secondary antibody for the detection of the antigen in the body. In this, first, the primary antibody is nurtured with antigen. Following this, a secondary antibody recognizes the primary antibody in the method. One of the benefits of the indirect method is it helps to get better signal strength, and it is versatile to use. Therefore, depending on the disease, it is better to choose the right method for the diagnosis and finding out the antigen. Other than this, one can also use the sandwich ELISA method.