Quantitative detection of orthophosphate in polyacrylamide gels

A one-step procedure for the detection of Pi-producing enzymes in polyacrylamide and agarose gels was developed using PPi hydrolysis by inorganic pyrophosphatase as a model reaction. The color reagent consists of acid molybdate, methyl green, and Triton X-305 and produces sharp greenish-blue bands in places of Pi accumulation. The color is stable and its intensity is linearily related to enzyme amounts in the gel.