Which of the following is the primary purpose of an ELISA test?

The primary purpose of an ELISA (Enzyme-Linked Immunosorbent Assay) test is to quantify protein concentration, specifically in the context of detecting and measuring specific proteins such as antibodies, antigens, or hormones in a sample. ELISA utilizes a solid-phase enzyme-linked immunosorbent method, where an antigen is immobilized to a surface, and detection is carried out using enzyme-conjugated antibodies. The amount of color change, which is detected spectrophotometrically, correlates directly with the concentration of the target protein present in the sample.

This method is widely used in clinical diagnostics and research to measure protein levels, making it a fundamental tool in various applications, such as disease diagnosis, vaccine development, and biomarker discovery. By quantifying specific proteins, researchers can obtain valuable data on biological processes or disease states, which is essential for both experimental and clinical settings.