dichlorophenolindophenol

Dichlorophenolindophenol, often abbreviated as DCPIP or DPIP, is a chemical compound used as a redox indicator. It is a dark blue crystalline solid in its oxidized form and turns colorless when reduced. This color change is the basis of its utility in various biochemical assays.

DCPIP is primarily employed to measure the rate of reduction reactions, particularly in the study of photosynthesis and respiration. In photosynthesis, it can act as an artificial electron acceptor, mimicking the role of NADP+. When illuminated, chloroplasts reduce DCPIP, causing a visible color change from blue to colorless. The rate of this decolorization is directly proportional to the rate of electron transport through the photosystems.

Similarly, DCPIP can be used to assess the activity of certain enzymes involved in dehydrogenation reactions. These enzymes typically transfer hydrogen atoms (and thus electrons) to an acceptor molecule. By using DCPIP as the acceptor, the rate of hydrogen transfer can be monitored by observing the reduction of DCPIP. This makes it a valuable tool in enzyme kinetics studies and in the analysis of biological samples for the presence of specific enzymatic activities. Its use is favored due to its distinct color change and relatively low cost.