Propidium iodide

Propidium iodide (PI) is a fluorescent intercalating agent that can be used to stain cells. It is often used in Flow cytometry to evaluate cell viability or DNA content in cell cycle analysis.

Chemical Properties

Propidium iodide is a member of the Iodide family, with a molecular formula of C27H34I2N4. It has a molar mass of 668.4 g/mol. It is a red-orange compound that is soluble in water and has a melting point of 300 degrees Celsius.

Usage

Propidium iodide is used in Biotechnology and Molecular biology as a nucleic acid stain in a range of applications. It binds to DNA by intercalating between the bases with little or no sequence preference and with a stoichiometry of one dye per 4-5 base pairs of DNA. PI also binds to RNA, necessitating treatment of cells with RNase to ensure specific staining of DNA.

Flow Cytometry

In flow cytometry, propidium iodide is a popular DNA stain to assess cell cycle phase. It can be used in conjunction with other dyes that stain for different cellular components, such as Annexin V, which stains for apoptotic cells.

Safety

Propidium iodide is considered hazardous and should be handled with care. It is a potential mutagen and should be used with appropriate protective clothing and eyewear.

See Also

• Flow cytometry
• Iodide
• Molecular biology
• Biotechnology
• Annexin V