Description: TMB Substrate Solution for ELISA Form: Liquid Directions for Use : 1. Equilibrate the TMB to room temperature. Add 50-100μL of the TMB Substrate Solution to each microplate well. 2. Incubate plate at room temperature for 15-30 minutes or until the desired color develops. 3. Stop reaction by adding 50-100μL of 2M sulfuric acid to each well. 4. Measure the absorbance of each well at 450nm.Components : TMB Chromogen Solution contains soluble TMB (3,3´,5,5´-tetramentylbenzidine) that is ideal for sensitive ELISA-based applications. TMB is a chromogenic substrate for horseradish peroxidase. Once oxidized by the enzyme, this substrate yields a blue product that absorbs at 370nm and 652nm. Adding sulfuric or phosphoric acid to stop the reaction changes the product to yellow that absorbs at 450nm and provides greater sensitivity than the blue product. TMB Chromogen Solution is supplied ready to use with no mixing required.Storage/Stability : Store at 4°C for one year. Do not freeze.