Protein-free, polymer-based blocking reagent, delivered as a 10x concentrate. To achieve a good signal-to-noise ratio in blotting, ELISA or other immunoassays , it is important to block nonspecific antibody binding sites. Protein based blocking solutions like skim milk or BSA solutions may not only block unspecific binding sites, but mask as well specific binding sites. With BlueBlock, the specific binding sites remain accessible while nonspecific reactions are suppressed, thus leading to an increase in signal intensity. It is suitable for colorimetric and chemiluminescence detection systems.