About Propidium Iodide
Propidium Iodide (PI) is an orange/red-emitting DNA intercalating dye that can be excited by the 532 nm green laser and captured with a 630/69 nm bandpass filter. Unbound, PI has an excitation peak at 493 nm and an emission peak at 636 nm. However, when PI is bound to DNA the excitiaton peak shifts to 535 nm and the emission peak shifts to 617 nm. PI is predominantly used in flow cytometry as a DNA stain evaluate cell viability or to monitor cell cycle analysis, or in microscopy to visualize the nucleus and other DNA-containing organelles. PI is a generic dye that is sold by multiple suppliers.