Propidium monoazide

Propidium monoazide

Names
IUPAC name 3-Amino-8-azido-5-{3-[diethyl(methyl)ammonio]propyl}-6-phenylphenanthridinium
Identifiers
3D model (JSmol)	Interactive image
ChemSpider	2299748
PubChem CID	3035529
InChI InChI=1S/C27H31N6/c1-4-33(3,5-2)17-9-16-32-26-18-21(28)12-14-24(26)23-15-13-22(30-31-29)19-25(23)27(32)20-10-7-6-8-11-20/h6-8,10-15,18-19,28H,4-5,9,16-17H2,1-3H3/q+1/p+1 Key: DXHWIAMGTKXUEA-UHFFFAOYSA-O InChI=1/C27H31N6/c1-4-33(3,5-2)17-9-16-32-26-18-21(28)12-14-24(26)23-15-13-22(30-31-29)19-25(23)27(32)20-10-7-6-8-11-20/h6-8,10-15,18-19,28H,4-5,9,16-17H2,1-3H3/q+1/p+1 Key: DXHWIAMGTKXUEA-IKLDFBCSAS
SMILES [N-]=[N+]=N\c3ccc2c1ccc(N)cc1[n+](c(c2c3)c4ccccc4)CCC[N+](CC)(CC)C
Properties
Chemical formula	C27H32N62+
Molar mass	440.582 g/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Propidium monoazide (PMA) is a photoreactive DNA-binding dye that preferentially binds to dsDNA. It is used to detect viable microorganisms by qPCR. Visible light (high power halogen lamps or specific LED devices) induces a photoreaction of the chemical that will lead to a covalent bond with PMA and the dsDNA. This will render the DNA non-amplificable by PCR. Dead microorganisms lose their capability to maintain their membranes, which leaves the "naked" DNA in the cytosol ready to react with PMA. Living organisms don't react to the PMA, as they have an intact cell membrane. After treatment with the chemical, only the DNA from living bacteria is usable in qPCR, allowing to obtain only the amplified DNA of living organisms. This is helpful in determining which pathogens are active in specific samples. The main use of PMA is in Viability PCR but the same principle can be applied in flow cytometry or fluorescence microscopy.

PMA was developed at Biotium, Inc. as an improvement on ethidium monoazide (EMA). PMA provides better discrimination between live and dead bacteria because it is excluded from live cells more efficiently than EMA.