EIA and ELISA are both laboratory tests commonly used to detect HIV. “EIA” stands for “enzyme immune assay” while “ELISA” stands for “enzyme linked immunosorbent assay. ... EIA is described as a group of binding assays in which the molecular recognition properties of antibodies are used.
ELISA (enzyme-linked immunosorbent assay) is a plate-based assay technique designed for detecting and quantifying soluble substances such as peptides, proteins, antibodies, and hormones. Other names, such as enzyme immunoassay (EIA), are also used to describe the same technology.
For most sera the RIA is 2-4 times more sensitive than the ELISA. With some human sera the difference in sensitivity is far more dramatic. ... With both the mouse autoantibodies and the monoclonal antibody, the RIA is 2-4 times more sensitive than the ELISA.
(1) Plate is coated with a capture antibody; (2) sample is added, and any antigen present binds to capture antibody; (3) detecting antibody is added, and binds to antigen; (4) enzyme-linked secondary antibody is added, and binds to detecting antibody; (5) substrate is added, and is converted by enzyme to detectable ...
Direct ELISAs use a conjugated primary antibody, while indirect ELISAs include an additional amplification step. In an indirect ELISA, an unconjugated primary antibody binds to the antigen, then a labeled secondary antibody directed against the host species of the primary antibody binds to the primary antibody.
Enzyme-linked Immunosorbent Assays (ELISAs) combine the specificity of antibodies with the sensitivity of simple enzyme assays, by using antibodies or antigens coupled to an easily-assayed enzyme. ELISAs can provide a useful measurement of antigen or antibody concentration.
ELISA stands for enzyme-linked immunoassay. It is a commonly used laboratory test to detect antibodies in the blood. An antibody is a protein produced by the body's immune system when it detects harmful substances, called antigens.
Advantages of ELISA Tests
The four major types of ELISA are indirect, direct, sandwich and competitive.
Four Types of ELISA
|Sandwich ELISA||High flexibility. High sensitivity. High specificity, since different antibodies bind to the same antigen for detection.|
|Competitive ELISA||High flexibility. High sensitivity. Best for the detection of small antigens, even when they are present in low concentrations.|
These two antibodies are normally referred to as matched antibody pairs. One of the antibodies is coated on the surface of the multi-well plate and used as a capture antibody to facilitate the immobilization of the antigen. The other antibody is conjugated and facilitates the detection of the antigen.
Why is ELISA so sensitive? ELISA is sensitive because if it was not washed well, then there will be false positives due to the enzyme binding to floating antibodies. The enzymes used have a high turn over rate and produces results rapidly. You just studied 10 terms!