Know About These Different Types of Elisa Tests

Elisa's full form is Enzyme-Linked Immunosorbent Assay and the sandwich Elisa principle is a powerful and sensitive technique which measures the antigen concentration level of an unknown sample.

In between two layers of antibodies, which are the capture and the detection antibody, the antigen of interest is quantified. The antigen must contain at least two antigenic epitope which is capable of binding to an antibody.

These antibodies such as monoclonal or affinity purified polyclonal can be used to detect or capture antibodies.

Elisa is like a diagnostic tool in pathology or medicines related to plants. This technique is used to measure protein levels, hormone levels, antibodies, peptides in the sample taken. There are 5 different types of Elisa tests:

Direct Elisa:

Direct Elisa is a simple test which also saves time. In this, the plastic plate is taken and the antigen is placed on it. To block other binding sites, another protein is added to the mixture. The enzyme is linked to an antibody in another place and then mixed to the absorbed antigen. Addition of substrate-enzyme detects and shows the presence of the antigen.

Indirect Elisa:

In indirect ELISA test, different detection antibodies are made with the use of the single labeled secondary antibody.

Sandwich Elisa:

In Sandwich Elisa Principle, the antigen is considered as a substance. Additional two layers of the antibody, such as detection antibody and capture antibody, are used to cover it. Shortly afterward, the result is evaluated.

In this test, two different types of antibodies are used such as monoclonal and polyclonal.

The simple epitope is recognized by a monoclonal antibody. It helps to improve the detection. Furthermore, it assists to measure any difference in the antigen. A polyclonal antibody uses the capture antibody to derive the maximum output from the antigen.

Competitive Elisa:

Competitive Elisa is the process of binding in which sample antigen is mixed with an additional antigen. This test is somewhat different from other sandwich Elisa troubleshooting tests.

In this test, if the sample is a high concentration of antigen then the signal is weak.

Elispot:

This test is used to detect and list down the antibody that are discharging cells. This test is used in the field of vaccine development, transplantation, humoral immunity, allergies, infectious diseases, autoimmunity, cancer, and TH1/TH2 analysis.

These are various types of Elisa Test which are conducted in the lab by a team of qualified and experienced lab technicians.

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Ethanmiller Joined: May 23rd, 2018