{"id":4151,"date":"2024-04-12T11:01:15","date_gmt":"2024-04-12T05:31:15","guid":{"rendered":"https:\/\/www.tutoroot.com\/blog\/?p=4151"},"modified":"2024-12-20T12:44:28","modified_gmt":"2024-12-20T07:14:28","slug":"what-is-elisa-technique-types-of-elisa-test-uses","status":"publish","type":"post","link":"https:\/\/www.tutoroot.com\/blog\/what-is-elisa-technique-types-of-elisa-test-uses\/","title":{"rendered":"What is ELISA Technique? Types of Elisa Test, Uses"},"content":{"rendered":"

Origin of Elisa Technique<\/span><\/b><\/h2>\n

The Enzyme-Linked Immunosorbent Assay, or ELISA, technique was first introduced in the early 1970s as a revolutionary method for detecting and quantifying biological substances. This groundbreaking technique quickly gained popularity due to its simplicity, sensitivity, and versatility.<\/span>\u00a0<\/span><\/p>\n

What is Elisa Technique?<\/span><\/b><\/h2>\n

ELISA is a powerful biochemical technique used to detect the presence of an antigen or antibody in a sample. It relies on an enzyme and substrate interaction to produce a measurable signal. This method has become an essential tool in various fields, including clinical diagnostics, research laboratories, and the pharmaceutical industry.<\/span>\u00a0<\/span><\/p>\n

Principle of ELISA<\/span><\/b><\/h2>\n

The principle behind ELISA is based on the specific binding of an antigen and an antibody. The antigen of interest is immobilized on a solid surface, such as a microplate. Subsequently, an enzyme-linked antibody is added, which binds to the antigen forming an antigen-antibody complex. The enzyme substrate is then added, resulting in a colour change that can be quantified using a spectrophotometer.<\/span>\u00a0<\/span><\/p>\n

Types of Elisa Test<\/span><\/b><\/h2>\n

ELISA assays can be classified into three main types based on the method of detection: indirect ELISA, sandwich ELISA, and competitive ELISA. Each type has its unique advantages and applications in various fields of research and diagnostics.<\/span>\u00a0<\/span><\/p>\n

Indirect ELISA<\/span><\/b><\/h4>\n

Indirect ELISA is a commonly used method for detecting antibodies in a sample. In this technique, the antigen is immobilized onto a solid surface, and the sample containing antibodies is added. If antibodies specific to the antigen are present in the sample, they bind to the immobilized antigen. Then, a secondary antibody labelled with an enzyme is added, which binds to the bound antibodies, forming a complex. The enzyme activity is detected using a substrate, indicating the presence of antibodies in the sample.<\/span>\u00a0<\/span><\/p>\n

Sandwich ELISA<\/span><\/b><\/h4>\n

Sandwich ELISA is highly sensitive and specific for detecting and quantifying antigens in a sample. In this technique, a capture antibody is immobilized onto a solid surface, and the sample containing the antigen is added. If the antigen is present, it binds to the capture antibody. Then, a detection antibody labelled with an enzyme is added, which binds to a different epitope on the antigen, forming a “sandwich” structure. The enzyme activity is detected using a substrate, indicating the presence and quantity of the antigen in the sample.<\/span>\u00a0<\/span><\/p>\n

Competitive ELISA<\/span><\/b><\/h4>\n

Competitive ELISA is used for quantifying the concentration of an antigen in a sample. In this technique, the antigen of interest is immobilized onto a solid surface, and a known amount of labelled antigen (conjugate) is added to the sample. The sample containing the unlabeled antigen competes with the labelled antigen for binding to the immobilized antibody. The amount of labelled antigen bound to the antibody is inversely proportional to the concentration of the unlabeled antigen in the sample, allowing for quantitative analysis.<\/span>\u00a0<\/span><\/p>\n

Complete the Elisa Technique Procedure<\/span><\/b><\/h2>\n

The ELISA technique involves several key steps, including coating, blocking, incubation, washing, detection, and analysis. Here’s a brief overview of the complete procedure:<\/span>\u00a0<\/span><\/p>\n

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  1. Coat the microplate with the antigen.<\/span>\u00a0<\/span><\/li>\n
  2. Block non-specific binding sites.<\/span>\u00a0<\/span><\/li>\n
  3. Add the sample or standard containing the antigen.<\/span>\u00a0<\/span><\/li>\n
  4. Wash the plate to remove unbound substances.<\/span>\u00a0<\/span><\/li>\n
  5. Add the enzyme-linked antibody.<\/span>\u00a0<\/span><\/li>\n
  6. Wash the plate again.<\/span>\u00a0<\/span><\/li>\n
  7. Add the enzyme substrate to produce a measurable signal.<\/span>\u00a0<\/span><\/li>\n
  8. Measure the colour intensity using a spectrophotometer.<\/span>\u00a0<\/span><\/li>\n<\/ol>\n

    Diseases that can be Diagnosed Using ELISA Method<\/span><\/b><\/h2>\n

    ELISA is instrumental in diagnosing various diseases, including:<\/span>\u00a0<\/span><\/p>\n