Phosphate is an important inorganic ion in biological systems and has many functions. Phosphate can turn on or off enzyme activity through the mediation of the various phosphatases and protein kinases in biological systems. Phosphate also plays an important role in mineralization processes and is a major stimulus of algal blooms mainly found in bodies of fresh water, because of run-off from areas of high fertilizer use.

The Phosphate Colorimetric Assay Kit provides a simple, fast and sensitive way for detection of phosphate over a wide range of concentrations in various samples based on colorimetric method. The assay uses a proprietary formulation of malachite green and ammonium molybdate which forms a chromogenic complex with phosphate ion that can be easily detected at 650 nm using a spectrophotometer or an ELISA plate reader. The kit can dectet 1 µM - 1 mM phosphate concentrations with a lower limit of approximately 0.1 nmol. The kit provides 500 assays using microtiter plates or 100 assays using 1 mL cuvettes.