Immunoassays/ELISA

Immunoassays are a class of analytical techniques where the reaction between an antigen and an antibody is used for the identification and quantification of the antigen in biological samples. Immunoassays are one the most commonly used techniques in clinical practice for oxidative stress assessment. The assays are often standardized and do not require expensive instrumentation. They are easy to perform and fast and provides a sensitive, automated, and high-throughput alternative for measuring a variety of oxidative stress biomarkers (e.g., protein carbonyl, nitrotyrosine, glutathionylated proteins, carbohydrate end-products, MDA adducts, 4-HNE-Protein adducts, OxLDL, isoprostanes (IsoPs), and DNA end-products). They are cost-effective with sensitivity and specificity comparable to conventional methods. More important, in situ analysis is possible with immunoassays. The versatility in the applications of immunoassays has also made these methods more popular in recent years. For these reasons, immunoassays play an important role in various bioanalytical settings such as clinical diagnostics, research, and therapeutic assessment. In fact, many tests have already been converted into commercial kits for this purpose and are reproducible and user-friendly. A detailed and thorough review of these assays is presented in this chapter with their challenges and applications.