PI

Propidium Iodide (PI), molecular formula C27H34I2N4, molecular weight 668.4, CAS number 25535-16-4, is a nucleic acid fluorescent dye, can be used to stain mammals, bacteria, yeast. It cannot penetrate living cell membranes, but can penetrate the cell membranes of dead cells and late apoptotic cells to stain the nucleus.