The assay is a competitive ELISA where the signal is inversely proportional to the amount of PI(3,4)P₂ produced.  This allows the user to measure the amount of PI(3,4)P₂ extracted from cells by means of standard 96 well ELISA format, eliminating the need for radioactivity and thin layer chromatography.  Once PI(3,4)P₂ has been extracted from cellular samples, it is incubated with a PI(3,4)P₂ detector protein, then added to the PI(3,4)P₂-coated plate for competitive binding.  A peroxidase-linked secondary detection reagent and colorimetric substrate is used to detect PI(3,4)P₂ detector protein binding to the plate.  The colorimetric signal is inversely proportional to the amount of PI(3,4)P₂ extracted from cells.