PMA (propidium monoazide) dye is a DNA modifier invented by scientists at Biotium. It is a photo-reactive dye that binds to dsDNA with high affinity. Upon photolysis with visible light, PMA dye covalently attaches itself to dsDNA. The PMA-modified dsDNA cannot be amplified by PCR. The dye is designed to be cell membrane-impermeable. Thus, in a population of live and dead cells, only dead cells are susceptible to DNA modification due to compromised cell membranes. This unique feature of PMA dye makes it highly useful in selective detection of live bacteria by qPCR. A bacterial sample can be first pre-treated with PMA under light to inactivate dsDNA from dead cells. DNA is then extracted and analyzed by PCR. Since Biotium first developed PMA dye, there have been numerous publications on the use of the dye in pathogenic bacterial detection related to food and water safety, medical diagnosis and biodefense; download the PMA Reference List. Please also see PMA in lyophilized format, catalog no. 40013. For viability PCR of gram-negative bacteria we highly recommend using our new PMA Enhancer (31038) in conjunction with PMA. PMA Enhancer for Gram Negative Bacteria was designed to improve PMA-mediated discrimination between live and dead gram-negative bacteria. When a sequence from a gram-negative bacteria is amplified by PCR, samples pre-treated with Enhancer show a decrease in the signal from dead cells, with no change in the signal from live cells. Biotium also provides strain-specific PMA Real-Time PCR Bacterial Viability kits with validated primers for 7 selected pathogens: M. tuberculosis, S. aureus, MRSA, Salmonella, E. coli, E. coli O157:H7 and Listeria. These kits provide everything that you need for the selective detection of your favorite species of live bacteria by real-time PCR.
- Molecular weight: 511
- Abs = 464 nm (before photolysis)
- Abs/Em = 510/610 nm (following photolysis and covalent attachment to DNA/RNA)
- Dark red solid soluble in DMSO or DMF
- Store at 4°C and protect from light at all times