How does the use of antibodies in an assay like ELISA improve specificity?

The use of antibodies in an assay like ELISA significantly improves specificity primarily because antibodies are designed to bind only to specific target proteins or epitopes. Each antibody is generated against a particular antigen, allowing it to recognize and attach to that molecule with high affinity and selectivity. This selectivity means that the antibody will usually ignore other proteins or substances that may be present in the sample, thereby reducing background noise and enhancing the clarity of the results.

For instance, in an ELISA, the capture antibody is immobilized on a solid surface and will only bind to the specific antigen of interest, while other proteins in the sample that do not match the antibody's target remain unbound. This targeted binding ensures that the detected signal is primarily derived from the specific protein being studied, leading to more reliable and accurate results.

In contrast, increasing sensitivity, amplifying signal, or providing a pH buffer does not directly relate to the specificity of the antibodies in an assay setting. Sensitivity relates to the assay's ability to detect low quantities of the target molecule, while signal amplification pertains to enhancing the results of the biochemistry involved but does not influence targeting specificity. A pH buffer is essential for maintaining the appropriate environment for the reactions in the assay but does not affect