Widely used in immunological assays such as Western blotting, ELISA, and immunohistochemistry. Serves as a blocking and washing buffer to reduce non-specific binding of antibodies to membranes or plate surfaces. The Tween-20 component acts as a mild surfactant that helps remove unbound reagents while preserving specific antigen-antibody interactions. Effective in maintaining assay specificity and lowering background noise, making it essential in detection steps involving primary and secondary antibodies. Commonly used after protein transfer and during antibody incubations to improve signal clarity and reproducibility.