The overall objective of this proposal is to validate SEDUM's non-hazardous, aqueous tetramethylbenzidine (TMB) formulation for horseradish peroxidase enzyme assays. One of the current safety issues associated with all commercial formulations of TMB is they all contain organic solvents. The final TMB product is a buffered aqueous solution that contains 15-20 percent organic solvent. Several of the solvents used are labeled as toxic substances such as, dimethylformamide, dioxane, and methanol. Some of the suppliers use dimethylsulfoxide but in combination with a hazardous solvent. SEDUM has developed a safe, aqueous formulation of TMB based on first stabilizing the TMB and then adding it to an aqueous buffer. Comparative studies with this new formulation with existing TMB products has produced similar data using commercial ELISA diagnostic products as controls. Data has been generated that indicates that this new formulation will satisfy the shelf life requirement of 18 months at 4 C. SEDUM now proposes to validate this process. The TMB stabilizing conditions need to be optimized. The appropriate buffer needs to be finalized that will produce a product that offers a safe reagent, has high assay sensitivity and the long-term stability of the final manufactured product.
