What is the primary purpose of the ELISA technology?

The primary purpose of ELISA (Enzyme-Linked Immunosorbent Assay) technology is to determine the presence of a specific antigen in a sample. This method utilizes antibodies that are linked to an enzyme, allowing for the detection and quantification of antigens in various samples, such as blood or other bodily fluids. When the antigen binds to the antibody, a substrate is added that reacts with the enzyme, producing a measurable signal—usually a color change. This signal's intensity correlates with the amount of antigen present in the sample, allowing for quantitative analysis.

In contrast, the other options involve different testing methodologies: detecting RNA typically involves techniques like RT-PCR, amplifying DNA is accomplished through methods such as PCR, and visualizing protein structures often relates to techniques like X-ray crystallography or electron microscopy. Each of these technologies serves distinct purposes and employs specific techniques that differ fundamentally from the functions of ELISA.