What is the primary function of an ELISA assay?

The primary function of an ELISA (Enzyme-Linked Immunosorbent Assay) is to identify target proteins using antibodies. This technique is widely utilized in biochemistry and molecular biology for its specificity and sensitivity. During an ELISA procedure, a sample is immobilized on a solid surface, and then a specific antibody that can bind to the target protein is introduced. The presence of the target protein can then be detected by a secondary antibody linked to an enzyme, which produces a measurable signal upon substrate addition. This allows for the quantification of the target protein based on the intensity of the signal generated.

Other methods mentioned involve different processes: quantifying protein concentration using UV absorption is a method to measure concentration, not a specific identification process like ELISA; amplifying protein samples is related to methods such as PCR for nucleic acids rather than protein analysis; and determining molecular weight is typically conducted using techniques like SDS-PAGE, which measure the size of proteins rather than identifying them directly. Therefore, identifying target proteins using antibodies is the hallmark of an ELISA assay, which underlies its practical applications in diagnostics and research.