What type of assay is commonly used to detect proteins in serum?

The Enzyme-linked immunosorbent assay, or ELISA, is widely utilized to detect proteins in serum due to its high sensitivity and specificity. This assay is based on the principle of antigen-antibody interactions, where a specific antibody is coated onto a plate and then incubated with a serum sample that may contain the target protein. If the protein is present, it will bind to the antibody, allowing for further detection using an enzyme-linked secondary antibody that recognizes the target protein. The bound enzyme can then be detected through a substrate reaction that produces a measurable signal, often a color change, making quantification straightforward.

ELISA is especially favored for its ability to process multiple samples simultaneously, making it efficient for large-scale testing, such as in clinical laboratories. Other methods, like Western blotting, are more complex and time-consuming, often requiring additional steps for protein separation and transfer. Radioimmunoassay, while effective for certain applications, involves handling radioactive materials, posing safety concerns and regulatory challenges. Fluorescent antibody assays can be used for various applications, including protein localization, but may require sophisticated equipment that is not as readily accessible as the ELISA setup. Thus, ELISA stands out as the most commonly used assay for detecting proteins in