Difference Between Western Blot and ELISA for HIV Test

May 25
07:08

2015

Wendy Kally

Wendy Kally

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There are many techniques of knowing the presence of the virus in human body and out of them ELISA and Western Blot are very popular today.

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There are many techniques of knowing the presence of the virus in human body and out of them ELISA and Western Blot are very popular today. The name of Western blotting,Difference Between Western Blot and ELISA for HIV Test Articles it is also called Western blot. ELISA is the abbreviation of enzyme-linked immunosorbent assay. Western blotting and enzyme-linked immunosorbent assay (ELISA) are widely used in the protein detection and they are especially widely used in protein detection. Western blotting and ELISA have widely application in scientific researches, industry and medical practice. There are many similarities in these two types of testing. However, there are also many differences.

What is Western blotting

Western blotting method is normally used with a high quality antibody directed against a desired protein. It is a method in molecular biology/biochemistry/immunogenetics to detect protein in a given sample of tissue homogenate or extract. This technique involves the use of gel electrophoresis to separate denatured proteins by mass. The proteins are then transferred out of the gel and onto a membrane and combine with antibodies specific to the protein. The secondary antiboy can be stained and pictured by a film. The film with the protein binds can be kept for a long time and scanned any time it needs to quantity the protein levels. As a result, researchers can examine the amount of protein in a given sample and compare levels between several groups. Other techniques also using antibodies allow detection of proteins in tissues and cells.

What is ELISA?

The enzyme-linked immunosorbent assay (ELISA) is a common laboratory technique which is used to measure the concentration of an antibody or antigen in solution. An ELISA test uses components of the immune system and chemicals to detect immune responses in the body. The ELISA test involves an enzyme which is a protein that catalyzes a biochemical reaction. It also involves an antibody or antigen. ELISA tests are widely utilized to detect substances that have antigenic properties, primarily proteins. The substances detected by ELISA testsinclude hormones, bacterial antigens and antibodies. Enzyme-linked immunosorbent assay (ELISA) have become household name for medical laboratories, manufacturers of in vitro diagnostic products, regulatory bodies, and external quality assessment and proficiency-testing organizations.

Both ELISA and Western Blot are called indirect tests, because they measure the immune system’s response to an infectious agent rather than looking for the components of the agent itself. Since ELISA detects HIV antibodies which the body starts to produce between 2-12 weeks after becoming infected with HIV, experts say that one should wait for at least 3 months after unprotected test to confirm for HIV AIDS. Western Blot is the most common method of testing to confirm positive results from ELISA test. Western Blot is used more as a confirmatory test as it is difficult to perform and requires high skills, and but its more accurate thanELISA as it can effectively distinguish between HIV antibodies and other antibodies.

Doctors commonly order an ELISA first to screen for the disease and then confirm the disease with a Western blot. However, current ELISA tests are not sensitive enough for screening and may miss over half the true cases. Because of this, the best antibody test to use for diagnosis is the Western blot.