Intercept (PBS) Protein-Free Blocking Buffers are formulated to provide highly efficient blocking and low background variability for replicable quantitative Western blots and other immunoassays. This buffer contains no proteins, for assays where use of animal-based products is prohibited. They are an excellent choice for biotin-streptavidin detection and suitable for a wide range of applications, including Western blots, In-Cell Western™ assays, and protein arrays. Intercept (PBS) Protein-Free Blocking Buffer is a ready-to-use blocker formulation in phosphate-buffered saline and is stored at 4 °C. It contains no sodium azide, making it suitable for both near-infrared or chemiluminescent detection.