Phosphate-citrate buffer is a common buffer used along with soluble horseradish peroxidase substrates such as o-phenylenediaminedihydrochloride (OPD) or tetramethylbenzidine (TMB). It gives a pH of 5.0 with an excellent buffering capacity. The phosphate-citrate buffer tablets can be used to prepare a 0.05 M phosphate-citrate, pH 5.0, buffer solution. These tablets elicit a fast, convenient, and accurate method for the synthesis of phosphate citrate buffer solutions. They remove the time-consuming and tedious process of weighing individual components in buffer preparation. Phosphate-citrate buffer tablets have been manufactured from the highest quality components to exacting physical and chemical specifications to ensure performance and lot-to-lot consistency. Phosphate-Citrate Buffer tablets, pH 5.0, have been formulated as a substrate buffer in immunoassay procedures.
One tablet dissolved in 100 mL deionized water yields a 0.05 M phosphate-citrate buffer, pH 5.0, at 25 °C. Store at room temperature.