Table of Contents
What is an enzyme immunoassay drug test?
An enzyme immunoassay (EIA) or an enzyme-linked immunosorbent assay (ELISA) is a blood or urine analysis that can help in the diagnosis of many infections and inflammatory conditions.
What does an immunoassay test for?
An immunoassay is a test that relies on biochemistry to measure the presence and/or concentration of an analyte. The analyte can be large proteins, antibodies that a person has produced as a result of an infection or small molecules.
What does a positive EIA test mean?
What do the test results mean? If a person tests positive for HIV on the ELISA test, they might have HIV. However, there can be false positives with the ELISA test. This means that test results indicate that the person has HIV when they actually do not.
How does drug immunoassay work?
Immunoassay. The IA drug test uses antibodies to detect the presence of selected drugs and/or their metabolites based on a predetermined cutoff threshold. 8 Immunoassay monitoring is the initial qualitative test to identify the presence of drug classes in the urine based on a detection threshold.
How accurate are immunoassay tests?
The index test provided false-positive results for non-opioid use in 44% or 83 of 120 patients. For illicit drugs, the false-positive rate by index test was 0% for cocaine, whereas it was 2% for marijuana, 0.9% for amphetamines, and 1.2% for methamphetamines.
Why are enzymes used in immunoassay?
Key Concepts and Summary. Enzyme immunoassays (EIA) are used to visualize and quantify antigens. They use an antibody conjugated to an enzyme to bind the antigen, and the enzyme converts a substrate into an observable end product. The substrate may be either a chromogen or a fluorogen.
How accurate is EIA test?
Although false negative or false positive results are extremely rare, they may occur if the patient has not yet developed antibodies to HIV or if a mistake was made at the laboratory. When used in combination with the confirmatory Western blot test, ELISA tests are 99.9% accurate.
How is EIA diagnosed?
EVH test develops EIA by hyperventilation of dry gas and the test achieves the same airway obstruction as training in cold and dry air. The test is better than the previously used methacholine challenge test.
How accurate is immunoassay drug test?
The accuracy of the initial drug screen, the immunoassay test, ranges between 92% – 98%. The accuracy of the GC/MS confirmatory test is virtually 100% from a scientific standpoint.
How can immunoassay be carried out?
Some immunoassays can be carried out simply by mixing the reagents and sample and making a physical measurement. Such assays are called homogeneous immunoassays, or less frequently non-separation immunoassays. The use of a calibrator is often employed in immunoassays.
Is enzyme immunoassay the same as ELISA?
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.