The Wash and Stop Solution for ELISA without Sulfuric Acid contains all of the reagents necessary for preparing wash buffer (10X PBS and Tween 20) and a non-sulfuric acid formulation stop solution for peroxidase-based ELISA or immunoassay applications, including Takara Bio’s EIA kits. The ELISA Wash Buffer components allow for the preparation of both detergent-free and Tween 20-containing wash solutions. The ELISA Stop Solution included with this product is intended for stopping the colorimetric reaction of 3,3′,5,5′- tetramethylbenzidine (TMB) substrate in horseradish peroxidase (HRP)-based ELISA detection. This Stop Solution does not contain the conventional reaction stop reagent, sulfuric acid (H₂SO₄). It is less hazardous than conventional sulfuric-acid containing stop solutions, yet effectively halts color development for peroxidase reactions with TMB substrate.