AAT Bioquest

Does propidium iodide stain apoptotic cells?

Posted October 26, 2022


Propidium iodide (PI) will not be able to stain early apoptotic cells due to the presence of an intact cell membrane. Late apoptotic cells, which are considered dead cells, can be stained by propidium iodide due to not having a cell membrane. It all connects to membrane permeability; PI will not stain cells that are protected by a cell membrane.  

Additional resources

Modified Annexin V/Propidium Iodide Apoptosis Assay For Accurate Assessment of Cell Death

Apoptosis and Necrosis

Cell Meter™ Fluorimetric Fixed Cell Cycle Assay Kit *Red Fluorescence Optimized for Flow Cytometry*