Enzyme-Linked Immunosorbent Assays (ELISAs) are some of the most common wet-lab proteomics assays in use today. The ELISA was born from an older assay design, the Radiometric Immuno-Assay. RIA uses radioactive reagents which, if not handled properly, pose a significant risk to human health and safety.
The first ELISA was developed to avoid this danger and to create a fast, simple and safe alternative. You can also buy bdnf elisa kits online from various sources.
Although RIAs are still used in some contexts, they have been largely replaced by the more secure and less technical ELISA. Like its predecessors, ELISA is an antibody-based method developed to quantitatively or qualitatively detect a specific analyte in a sample.
ELISA tests are usually (but not necessarily) protein, and sample types can range from raw biological fluids (eg, plasma, serum, urine, sweat) to fine cell culture media or pure recombinant protein in solution.
Although there are many different types of ELISA, the basic principle of the assay is very simple: An enzyme conjugated to an enzyme (usually a peroxidase) binds to an analyte immobilized on solid support (usually a 96-well microtiter plate).
The sample is washed and the unbound antibody is removed. A colorless chromogenic substrate is then introduced and the enzyme conjugate catalyzes the reaction that converts the colorless substrate to a dark-colored derivative.
The color change is used to confirm the presence of an analyte in qualitative analysis, and in quantitative analysis, the degree of colorimetric shift can be compared with the observed change from a standard set of known concentrations to estimate the amount of analyte present.