What does an ELISA test primarily detect?

An ELISA test, which stands for Enzyme-Linked Immunosorbent Assay, is primarily designed to detect antibodies or antigens present in a sample. This test is widely used in various fields, including medical diagnostics and research, due to its ability to quantify specific proteins, hormones, or antibodies that are indicative of an immune response or the presence of a specific pathogen.

In the context of detecting disease, the presence of antibodies can indicate prior exposure to a pathogen, while the detection of antigens can indicate an active infection. The sensitivity and specificity of ELISA make it a valuable tool for diagnosing infections, autoimmune disorders, and monitoring immune responses, among other uses. This versatility in detecting both antibodies and antigens is what makes the option regarding antibodies or antigens the most accurate in describing the primary function of the ELISA test.