DCPIP

DCPIP (2,6-dichlorophenolindophenol) is a synthetic indophenol dye used as a redox indicator in biochemical and analytical applications. In its oxidized form it is intensely blue; when reduced it becomes colorless, a reversible change that makes it useful for visualizing electron transfer reactions. The compound is commonly supplied as the water‑soluble sodium salt.

In plant physiology and biochemistry, DCPIP is widely used as an artificial electron acceptor to study photosynthetic electron transport. Chloroplast preparations or isolated photosystems reduce DCPIP in place of natural acceptors, and the rate of decolorization can be monitored spectrophotometrically to assess electron flow. DCPIP is also employed in titrations to measure vitamin C (ascorbic acid) content because ascorbate reduces the dye, producing a clear endpoint.

Beyond photosynthesis and ascorbate assays, DCPIP serves as a general redox indicator in laboratory experiments and teaching demonstrations. Its redox behavior involves reversible one- or two‑electron transfer to give a reduced, colorless leuco form.

DCPIP should be handled with standard laboratory precautions: it is an irritant and may be harmful if ingested or inhaled, and solutions can be light- and air‑sensitive under some conditions. Disposal should follow institutional and regulatory guidelines for laboratory chemicals.