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This product improves PMA- and PMAxx™-mediated discrimination between live and dead gram-negative bacteria when performing viability PCR.
PMA Enhancer for Gram Negative Bacteria improves PMA- and PMAxx™-mediated discrimination between live and dead gram-negative bacteria.
The mechanism by which Enhancer improves live/dead discrimination has not been determined. It may improve passive permeability of dead cell walls or membranes to the dye, and/or improve access of the dye to the dead cell DNA.
Viability PCR is a powerful technology for the sensitive and rapid detection of viable microorganisms. Unlike time-consuming culturing methods, qPCR is a fast and sensitive method of detection. However, normal qPCR does not distinguish between live and dead cells. With v-PCR using PMAxx™ or PMA, you get the speed, sensitivity and specificity of PCR, plus quantifiable viability. And because no culturing is required, you can even detect viable but not culturable (VBNC) bacteria. The v-PCR technology can be applied not only to bacteria but to other organisms like yeast, viruses, eukaryotes, and archaea.
To learn more about the advantages of determining microbial or cell viability using viability PCR, visit the Viability PCR Technology Page.

E. coli were killed with mild heat treatment (56°C for 3 hrs) and treated with PMAxx™ or PMAxx™ + Enhancer, followed by light exposure using PMA-Lite™, DNA purification, and qPCR with Fast EvaGreen® qPCR Master Mix. dCt values were calculated by subtracting the Ct without dye from the Ct with dye. Only dead cells treated with PMAxx™ + Enhancer showed a large dCt, indicating that the dye successfully inhibited PCR of dead cell DNA.
Download list of curated PMA and PMAxx™ References and a list of PMA and PMAxx™ Validated Bacterial Strains.
Download list of curated PMA and PMAxx™ References and a list of PMA and PMAxx™ Validated Bacterial Strains.
Note: Do not remove the cover or introduce liquids to the interior of the PMA-Lite.
The LEDs in the PMA-Lite™ and PMA-Lite™ 2.0 have a wavelength that is 465-475 nm and a brightness of approximately 600-800 millicandela (mcd). These are nominal values provided for reference use only, individual LED wavelength and brightness are not a calibrated specifications for the device.
There are three LEDs in each well (one bottom, two side) that provide illumination around each sample tube for efficient photoactivation.
The illumination in each well on the PMA-Lite far exceeds what is required for photocrosslinking of the viability dyes EMA, PMA, or PMAxx™ to nucleic acids. Therefore, any variability in brightness of the PMA-Lite LEDs should not significantly affect the v-PCR results. If performance verification is required, we recommend doing a functional PMA-PCR assay to verify that PMA-treated samples photoactivated in the device give qPCR results within an acceptable range. Mixing the samples during photoactivation and using longer illumination times may be necessary if the samples are complex and not fully transparent to light.
For other related FAQs, see Is illumination even across all positions in the PMA-Lite™ device? and Can I use PMA or PMAxx™ with environmental samples?
PMA is stable after dilution to 0.2 mM in water as long as it is protected from light and can be stored in the same way as the 20 mM stock solution.