In an enzyme-linked immunosorbent assay (ELISA), what does the inclusion of serum from healthy volunteers help to determine?

In an enzyme-linked immunosorbent assay (ELISA), the inclusion of serum from healthy volunteers is primarily used to assess specificity. Specificity refers to the ability of the assay to correctly identify the target analyte, distinguishing it from other substances. By using serum from healthy individuals, the assay can establish a baseline of normal immunological response, which helps to determine whether the assay is accurately recognizing only the intended antigen and not cross-reacting with other components present in the serum.

When healthy serum is included, it allows for the detection of false positives that could arise from non-specific binding of antibodies in the test. If the ELISA shows positive results with the serum from healthy individuals, this indicates that the assay may not be specific enough for the target antigen. Thus, evaluating the response to healthy serum serves as a critical control to validate the specificity of the assay.

This focus on specificity is crucial in various diagnostic applications to ensure accurate results and minimize misinterpretation of data that could lead to inappropriate clinical decisions.