ELISA Kits and Their Benefits: A Powerful Scientific Tool

ELISA Kits and Their Benefits: A Powerful Scientific Tool – Enzyme-Linked Immunosorbent Assay (ELISA) is a test developed in 1974 to confirm HIV. It is a versatile and more straightforward test with many advantages. ELISA uses antibodies in the immune system and other chemicals to detect the immune response. The test contains an antibody or antigen that creates a reaction to provide a positive or negative result. An antigen is a foreign agent like a virus or bacteria that triggers your body’s immune system. At the same time, an antibody is a production in response to the trigger to attack the antigen.

The test shows results by using a microtiter plate that contains a certain amount of protein or antigen, and when exposed, the reaction produces a color change. A microtiter is a plate with dents used as test tubes. Uses for ELISA include identifying HIV status and allergic diseases. Elisa test detects hormones, viral antigen, bacterial antigen, antibodies created by the body in response to infection and vaccination.

ELISA kits are tests that contain chemicals needed to detect antibodies concerning infectious conditions; the kits are available to anyone for purchase. The most common type of ELISA test is the pregnancy test. It contains antibodies that will combine with a hormone called Human Chorionic Gonadotropin (HCG) present in blood or urine to determine the diagnosis. The reaction to the hormone produces color change or the plus sign to show if the result is positive.

Types of ELISA test

There are four types of ELISA tests.

Direct ELISA

This test has a polystyrene plate detecting and measuring a sample’s targeted protein, hormone, or antibody. Antigen in the plate binds with a target protein present in the sample and reaches the surface of the plate. This reaction provides the diagnosis. The test requires one antigen, which shortens the steps needed to perform it. Direct ELISA requires four steps: Plate Coating, Plate Blocking, Antibody Incubation, and Detection.

The first step, Plate Coating, involves diluting the antigen to a specific concentration, coating the polystyrene plate with the dilution, incubating the plate overnight at 4°C, disposing of the solution, and washing the plate at least three times. The Plate Blocking step blocks protein-binding areas on the plate and is incubated at room temperature for two hours. The next step is Antibody Incubation, where antibody dilution from a sample is added to the plate and left at room temperature for one or two hours. In each step, the lab technician washes the plate three times.

Finally, in the Detection phase, a substrate solution is added to detect the targeted protein by changing color; a stop solution follows this to halt the reaction and provide a diagnosis.

Indirect ELISA

This type of test uses two primary and secondary antibodies for a two-step binding process for detection. In the first step, an unlabeled primary antibody binds to the antigen present in the sample, and a labeled secondary antibody is added to the primary and binds. The test procedure follows the same steps as Direct ELISA.

Sandwich ELISA

The test is less common but efficient to detect antigens; most commercial pair tests use this method. The sample enzyme is “sandwiched” between two antibodies; the first antibody captures and pulls down the antigen while the second detects and quantifies antigens with high accuracy.

Competitive ELISA

Competitive is similar to the Sandwich test, a primary and competing antibody is added to the sample. The higher the presence of antigen in the sample, the less the amount of antibody will bind, thus its name, “Competitive.

Benefits of ELISA

Effective

ELISA tests are simple, highly sensitive, easily automated, and detect antigens and antibodies. The tests are straightforward and better than traditional laboratory tests; microplates used for ELISA tests offer quick results in three hours. Moreover, they are cost-efficient and eco-friendly as they don’t need expensive radiation or many organic solvents.

Speedy Results

Commonly, labs have ELISA automated processing systems to carry various tests. Some labs have machines with liquid handling systems to carry up to 15 tests each day from start to finish; this significantly reduces costs. The detection of both antigens and antibodies makes ELISA tests highly flexible.

Used in Different Sectors

The technology is excellent for blood screening and detecting infections like HIV, making it convenient to test blood transfusion and prevent spreading infections. Another sector that benefits from ELISA technology is the food industry. The tests detect allergens and toxins for specific drugs.

Unique Characters of Each Test

For the Sandwich ELISA test, the sample does not need to go through the purification test, unlike the Direct and Indirect, where each stage requires cleaning three times, and it is up to five times more sensitive than Direct and Indirect. Indirect is widely accessible and economical because it requires few antibodies. The test is sensitive for accurate detection.

Conclusion

ELISA technology is efficient and effective; its common use provides accurate and reliable results. The test can diagnose other diseases like rotavirus, Lyme disease, Zika virus, etc. Its primary purpose is to screen and determine whether in-depth tests are necessary, which may help rule out the possibility of having such infections. Commercially available tests require a sample from the patient, like blood or urine, and they are affordable and easy to use.

Author: Kathleen of cannabis2biz

Publisher: International Pain Foundation, iPain