Key Features of PiColorLock™ - phosphate detection reagent:


  • Colorimetric Assay – competitor assays are radioactive.
  • Special additive ensures low backgrounds with acid-labile substrates.
  • Unparalleled stability of phosphate-dye complexes.
  • Reagent is compatible with almost any assay buffer.
  • No inhibition of color development by high concentrations of protein.
  • Stable reagent formulation - long shelf life.


Colorimetric assays for phosphate detection are invariably based on the formation of colored complexes between an inorganic phosphate and a dye molecule under acidic conditions.

phosphate assay

PicolorLock™ Gold has also been designed to:

  • Prevent background signals arising from non-enzymatic (i.e. acid) hydrolysis of the substrate. The figure below shows ATP incubated in three detection reagents. A steadily rising background signal is seen with competitor reagents, whereas PiColorLock™ gives baseline readings.

ATPase assay, phosphate assay

  • Have a large linear range, thus reducing the need for sample dilution.

ATPase assay, phosphate assay

For more information, please watch our webinar on drug screening-assays for phosphate-generating enzymes below:


Related Reagents

PiBind™ resin provides a quick and easy way to remove contaminating Pi from buffers and from samples derived from cells and tissues.

High Throughput Colorimetric ATPase and GTPase assay kits. These non radioactive colorimetric assay kits use a 96 well format and all the necessary reagents are supplied for measuring enzyme activity and are ideal for high throughput drug screening.