Propidium iodide

Propidium iodide (or PI) is a fluorescent intercalating agent that can be used to stain cells and nucleic acids. PI binds to DNA by intercalating between the bases with little or no sequence preference. When in an aqueous solution, PI has a fluorescent excitation maximum of 493 nm (blue-green), and an emission maximum of 636 nm (red). After binding DNA, the quantum yield of PI is enhanced 20-30 fold, and the excitation/emission maximum of PI is shifted to 535 nm (green) / 617 nm (orange-red).^[1] Propidium iodide is used as a DNA stain in flow cytometry to evaluate cell viability or DNA content in cell cycle analysis, ^[2] or in microscopy to visualize the nucleus and other DNA-containing organelles. Propidium Iodide is not membrane-permeable, making it useful to differentiate necrotic, apoptotic and healthy cells based on membrane integrity.^[3][4] PI also binds to RNA, necessitating treatment with nucleases to distinguish between RNA and DNA staining.^[5] PI is widely used in fluorescence staining and visualization of the plant cell wall.^[6]

Propidium iodide

Identifiers
CAS Number	25535-16-4 Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:51240 Y
ChEMBL	ChEMBL345124 Y
ChemSpider	94732 Y
ECHA InfoCard	100.042.786
PubChem CID	104981
UNII	TP416O228T Y
CompTox Dashboard (EPA)	DTXSID20894084
InChI InChI=1S/C27H33N4.2HI/c1-4-31(3,5-2)17-9-16-30-26-19-22(29)13-15-24(26)23-14-12-21(28)18-25(23)27(30)20-10-7-6-8-11-20;;/h6-8,10-15,18-19,29H,4-5,9,16-17,28H2,1-3H3;2*1H/q+1;;/p-1 Y Key: XJMOSONTPMZWPB-UHFFFAOYSA-M Y InChI=1/C27H33N4.2HI/c1-4-31(3,5-2)17-9-16-30-26-19-22(29)13-15-24(26)23-14-12-21(28)18-25(23)27(30)20-10-7-6-8-11-20;;/h6-8,10-15,18-19,29H,4-5,9,16-17,28H2,1-3H3;2*1H/q+1;;/p-1 Key: XJMOSONTPMZWPB-REWHXWOFAB
SMILES CC[N+](C)(CC)CCC[n+]1c2cc(N)ccc2c3ccc(N)cc3c1c4ccccc4.[I-].[I-]
Properties
Chemical formula	C27H34I2N4
Molar mass	668.3946
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

See also

• Viability assay
• Vital stain
• SYBR Green I
• Ethidium bromide

References

1. "Propidium Iodide". Thermo Fisher Scientific. 2019-11-14. Retrieved 2019-11-14.
2. "Propidium Iodide Solution - BioLegend". Archived from the original on 10 February 2015. Retrieved 10 January 2015.
3. Lecoeur H (2002). "Nuclear apoptosis detection by flow cytometry: influence of endogenous endonucleases". Exp. Cell Res. 277 (1): 1–14. doi:10.1006/excr.2002.5537. PMID 12061813.
4. "Propidium Iodide". ThermoFisher.
5. Suzuki T, Fujikura K, Higashiyama T, Takata K (1 January 1997). "DNA staining for fluorescence and laser confocal microscopy". J. Histochem. Cytochem. 45 (1): 49–53. doi:10.1177/002215549704500107. PMID 9010468.
6. Bidhendi, AJ; Chebli, Y; Geitmann, A (May 2020). "Fluorescence Visualization of Cellulose and Pectin in the Primary Plant Cell Wall". Journal of Microscopy. 278 (3): 164–181. doi:10.1111/jmi.12895. PMID 32270489. S2CID 215619998.