Propidium monoazide，1MG，SML3448-1MG，Sigma

Biochem/physiol Actions

Propidium derivative that allows light-induced crosslinkage to DNA for highly selective live-dead cells analysis by PCR or fluorescence microscopy.
Propidium monoazide (PMA) is a propidium derivative with an azide group that allows crosslinkage to DNA upon light exposure. PMA is only permeable to bacteria with compromised membrane integrity, making it highly selective for sick/dying/dead cells over healthy cells. PMA is typically added to cell samples (50 μM for 1-15 min in the dark) prior to cross-linking induction (650-W halogen light source), washing and DNA extraction. Due to its higher charge, PMA (+2) is less permeant to live cells and more selective than ethidium monoazide/EMA (+1) for dead cells. The stained cells can also be viewed and analyzed by fluorescence microscopy.