ELISA Tests (cont.)
Charles Patrick Davis, MD, PhD
Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.
John P. Cunha, DO, FACOEP
John P. Cunha, DO, is a U.S. board-certified Emergency Medicine Physician. Dr. Cunha's educational background includes a BS in Biology from Rutgers, the State University of New Jersey, and a DO from the Kansas City University of Medicine and Biosciences in Kansas City, MO. He completed residency training in Emergency Medicine at Newark Beth Israel Medical Center in Newark, New Jersey.
In this Article
- What is ELISA?
- What is an ELISA test?
- What is the use of an ELISA test?
- What is an ELISA kit?
- How do health care workers perform an ELISA test?
- How does ELISA testing work?
- What are the types of ELISA tests? What is a direct ELISA?
- What are the advantages of ELISA testing?
- How do people prepare for an ELISA test? Is an ELISA test painful? What risks are involved with an ELISA procedure?
- How long does it take to get ELISA test results?
- What do the results of an ELISA test mean?
What are the types of ELISA tests? What is a direct ELISA?
There are four types or kinds of ELISA tests:
- Direct ELISA: attachment of an antigen to a polystyrene plate followed by an enzyme-labeled antibody that can react with the antigen and a substrate that can be measured
- Indirect ELISA: attachment of an antigen to a polystyrene plate followed by an unlabeled or primary antibody followed by an enzyme-labeled antibody that can react with both the primary antibody and substrate
- Sandwich ELISA: A capture antibody is attached to the polystyrene plate, then antigen is added that specifically attaches or captures the antigen. A second antibody, also specific for the antigen but not the same as the capture antibody is added and "sandwiches" the antigen. This second antibody is then followed by an enzyme-labeled antibody specific for the second antibody that can react with a substrate that can be measured
- Competitive ELISA: This test is like the sandwich ELISA but involves the addition of competing antibodies or proteins when the second antibody is added. This results in a decrease in the substrate signal that is generated. This test is considered to give good, highly specific results.
What are the advantages of ELISA testing?
ELISA tests are generally good and accurate tests. They are considered highly sensitive and specific (accurate) and compare favorably with other methods used for the detection of substances in the body. The ELISA testing method is more straightforward and easier to perform than older laboratory techniques, which often required radioactive materials.
How do people prepare for an ELISA test? Is an ELISA test painful? What risks are involved with an ELISA procedure?
In general, people do not need to prepare for an ELISA test. The test is done in a lab. If your blood is required, the only hurt is in blood collection. The risks associated with an ELISA test are rare and associated with blood withdrawal (infection, vessel damage, for example).
Get tips and advances in treatment.