ELISA kits are major discoveries in the research world. Their simplicity and easy-to-follow procedure make them the best for blood samples and the detection of various substances in the blood, such as antibodies, proteins, infections, and viruses.
The following article will look at a general overview of ELISA kits, focusing on how they work and their applications.
What Are ELISA Kits?
ELISA kits are simple, convenient, and efficient tools used to detect, analyze, and quantify substances of interest in a given sample. ELISA kits are primarily used in detecting a hundred different molecules and substances, such as growth factors, cytokines, drugs, infectious diseases, proteins, and antibodies.
Type of ELISA
Researchers apply four major types of ELISA. They differ in how they work and their principles. They include;
Direct ELISA detects antigens using a specific antibody. The antigen is deactivated on the surface of a given multi-well plate.
The indirect ELISA technique uses two steps in the detection process. First, the primary antibody binds to the target specific to a given antigen. Secondly, the secondary antibody binds to the primary antibody to allow detection. The indirect ELISA Technique can also detect specific antibodies in a serum sample.
Sandwich ELISA is the most commonly used technique. It requires two antibodies, known as matched antibody pairs, specific to a given antigen. One of the antibodies is coated on the surface of the multi-well plate, while the other one is conjugated to help detect the antigen. The antibody coated on the multi-well plate is used to immobilize the antigen.
Competitive ELISA is also known as competitive immunoassay or inhibition ELISA. It is used to measure and analyze the concentration of antigens in a given sample. It does this through the detection of signal interference.
How ELISA Kits Works
ELISA assays work differently depending on the type of ELISA technique applied. However, commonly, ELISA immobilizes the antigen against a solid surface. The antibody is then conjugated with molecules to help detect the specific antigen.
Multi-well plate provides a solid surface for immobilizing the antigen in the ELISA assay. Immobilization of these antigens helps separate specific antigens from other components in the sample. This feature makes ELISA assay the most straightforward technique to carry out multiple samples simultaneously.
Advantages Of ELISA Kits
High Sensitivity and Specificity
ELISA kits are very sensitive as they can detect antigens using antibodies at any given level or manner. They are also specific as they can detect the required substance in the sample without interfering with other components.
ELISA kits for commercial and research purposes are available in different plate formats, which can be adapted depending on individual needs.
Easy to perform
The procedure applied in ELISA assay is simple and easy to follow. It also requires little time and no experience or skill needed.
ELISA kits can help detect and analyze the concentration of antigens in a given sample.
Possibility to test various sample types
Using ELISA Kits, you can easily test various samples to detect the required substances. For example, you can use urine, saliva, plasma, tissue extracts, serum, and cellular.
Application of ELISA Kits
Since its invention, ELISA kits have been widely used for various purposes. Some of its uses include;
Diagnosis of Infectious Diseases
ELISA kits are used to detect infectious agents and the antibody response in a host. They are also used to identify infected individuals who require treatments and monitoring. They are also used in epidemiological management and monitoring.
Detection of Food Allergens
Due to their high sensitivity, ELISA kits help detect any food allergens that may adversely affect individuals if consumed. However, there are some food processing that may affect the detection of ELISA, such as heating. This is because heating has effects on allergen’s conformation.
Biosimilars and Biopharmaceutical Testing
Due to the manufacturing of biosimilar drugs, it is necessary to compare and prove the similarity of these drugs with other drugs they tend to emulate. ELISA kits are used to determine this similarity using factors such as impurity detection and concentration level of the drugs.
Cancer Biomarker Testing
ELISA assay can significantly help to detect, analyze, and quantify known biomarkers using a non-invasive technique. Cancer biomarkers are consistently detected in blood samples; hence ELISA kits are appropriate tools for such testing.
Forensic Drug Testing
ELISA kits can screen and test hard drug traces in blood and urine samples. For example, it’s possible to detect traces of cannabinoids, cocaine, opiates, methadone, and amphetamines in any given sample. Though liquid samples are easier to use with ELISA kits, solid samples such as hair can also be used in ELISA testing.
ELISA kits can detect the human Chorionic gonadotropin hormone in a urine sample. This hormone is usually synthesized during pregnancy.
ELISA Kits can effectively detect and quantify traces of autoimmune diseases. For example, they can test the presence of rheumatoid arthritis and lupus.
The simplicity and effectiveness of ELISA kits make them the most effective tools for detecting any substance in a given sample. Unlike other kits that only use liquid samples, ELISA kits prove effective using solid samples. You can use the ELISA kits to detect, analyze, and quantify any substance of interest at ease and very fast.