In the realm of biology, ELISA tests are one of many ways that we find and measure soluble substances in the world around us. They are used for many different things, all of which we have covered in this short guide.
So, join us as we cover what ELISA means and how these handy tests work. Maybe you need to work with ELISA kits or you just want to try them out yourself, in which case you’ll need the right equipment. To get started, you’ll need to get your hands on some MyBioSource ELISA Test Kits.
What Does ELISA Mean?
ELISA stands for Enzyme-Linked Immunosorbent Assay. Sometimes, it is abbreviated to EIA too. If you didn’t know, ‘assay’ is another word for a test, typically for a substance and undertaken in a scientific laboratory setting. Assays are vital for the work of many biologists and chemists who need to figure out what certain substances are and what they are made of. ELISA tests are a plate-based testing technique that is capable of detecting a wide variety of substances – mainly proteins, glycoproteins, antibodies, hormones, and peptides.
How ELISA Tests Work
So, how do ELISA tests work? As a plate-based assay, they rely on microplates that are used to house a macromolecule. This is the substance that is being tested, like a protein or antigen. Let’s go with antigens as an example. Once immobilized on the microplate, an antibody is added that is connected with a reporting enzyme and mixed in a substrate. The enzyme reacts with substances in the antigen, creating a visible stimulus that can be identified and measured. This specific interaction between the antigen and the appropriate antibody is important for ELISA tests, otherwise, the results could be obscured, inconclusive, or incorrect.
They use 96-well plates that allow for extensive testing of multiple samples, guaranteeing the veracity of any results that are drawn from those samples. In order for certain macromolecules to stick in the wells, like antigens and antibodies, absorbent plates may be required. ELISA kits aren’t made the same – different tests are better for detecting and measuring different substances from the human body and the world around us. A popular form of ELISA test is the sandwich ELISA. This is where two antibody sets are combined to detect secreted substances.
The test is carried out in the following steps:
- ELISA plates are coated with the capture antibody.
- Excess material is removed/washed from the plate.
- The target sample is added to the capture antibody, any antigens will bind to it.
- For best results, multiple tests and concentrations are used.
- Excess samples are washed away again if needed.
- A detection antibody is added, typically labeled with an enzyme that can bind to the target antigen.
- A substrate is added. Most ELISA tests are chromogenic, meaning they convert substrates into colored products.
- This allows for the concentration of antigens or other target substances in the sample to become visible.
- Using optical density, the concentration can be calculated and recorded.
Why ELISA Tests Are Used
Like many basic ways of testing substances, ELISA testing is used for a wide variety of things. If a substance can be separated from an organism and contain evidence of specific biological activities, it can be tested through the ELISA method.
Here are some examples that are relevant to human beings:
- Blood and blood-related cells can be diagnosed with HIV infection.
- Substances taken from pregnant women can be used to diagnose pregnancy.
- Similarly, substances can be tested for Lyme disease, Zika virus, syphilis, and toxoplasmosis.
- Mucous cells can be ELISA tested to diagnose the presence of squamous cell cancer in the skin.
Those are just some of the ways that ELISA tests can be used to discover and treat many human problems. How the findings are used varies between applications. Naturally, many of the examples above are for diagnostics purposes, so patients and other organisms can be effectively treated now that their ailment has been confirmed at a molecular level.
That’s pretty much everything you need to know about ELISA tests. You should now know what ELISA means, what the tests do, and the things that they are most commonly used for. More knowledge about how these tests can be used and applied will come with expertise in fields like biology, where handling, identifying, and measuring substances is necessary. These tests are invaluable and used in many laboratories and workshops around the world, so knowing how they work is important.