Support

Quick links
Frequently asked questions - categories
Ask a question
Contact Us
+1

VIABILITY PCR

PMAxx™ and PMA Viability PCR Dyes

Dead cell-specific dyes covalently modify DNA, allowing selective PCR amplification from live cells
Improve live/dead discrimination with PMAxx™
Improve PMA & PMAxx™ modification of dead gram-negative bacteria
LED photolysis devices for tubes or plates
Everything you need for v-PCR of common strains

VIABILITY PCR


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 PCR 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 and viruses.

How does v-PCR work?

PMAxx™ and PMA are photoreactive dyes with high affinity for DNA. The dyes intercalate into dsDNA and form a covalent linkage upon exposure to intense visible light. The reaction inhibits PCR amplification of modified DNA templates by a combination of removal of modified DNA during purification and inhibition of template amplification by DNA polymerases. Because the dyes are cell membrane-impermeable, when a sample containing both live and dead bacteria is treated with dye, only dead bacteria with compromised cell membranes are susceptible to DNA modification. In a real-time PCR reaction, dead cell DNA will show delayed amplification and higher Ct than live cells. In a mixed population, v-PCR permits quantitation of cell viability.

Principal of viability PCR with PMA or PMAxx™ dyes.The membrane impermeable dyes selectively enter dead cells and modify their DNA. Modified DNA is not amplified, allowing quantitation of viable cell DNA.
Example of viability qPCR of untreated or heat-killed <em>E. coli</em>with PMA dye. PMA treatment eliminates dead cell DNA, resulting in a large delay in Ct compared to live or untreated cells. NTC: no template control.

Back to top


PMA & PMAXX™ DYES FOR V-PCR


PMA is the original dye developed at Biotium for v-PCR. It has been validated in a wide variety of bacterial strains, as well as yeast and viruses (see PMA References. However, while PMA is generally effective at differentiating between live and dead bacteria by qPCR, it does not completely eliminate PCR products from dead cell DNA. This could potentially give false positive results.

PMAxx™ was designed by Biotium scientists to be a superior alternative to PMA. PMAxx™ is much more effective at eliminating PCR amplification of dead cell DNA, and therefore provides the best discrimination between live and dead bacteria.

Download the PMA™ and PMAxx™ flyer to learn more.

Live or dead bacteria treated with either PMA or PMAxx™ prior to qPCR. Dead bacteria treated with either PMA or PMAxx™ show delays in amplification compared to either live cells, or untreated dead cells. Bacteria treated with PMAxx™ show a larger delay than those treated with PMA. Therefore PMAxx™ is better able to differentiate live vs dead bacteria by viability PCR.

PMA & PMAxx™ for Viability PCR
Product NameCatalog No.Features
PMAxx™, 20 mM in H2O40069•    Next-generation vPCR dye
•    Gives the best live/dead discrimination
PMA Dye40013•    Original vPCR dye developed at Biotium
•    Validated in hundreds of publications and a wide variety of organisms
PMA Dye, 20 mM in H2O40019

Back to top


PMA ENHANCER FOR GRAM-NEGATIVE BACTERIA


PMA Enhancer for Gram Negative Bacteria was designed to improve discrimination between live and dead gram-negative bacteria during viability PCR. PMA Enhancer is provided as a 5X solution, and is added to a sample before the addition of viability dye. 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. PMA Enhancer is compatible with PMAxx™ as well as PMA. PMAxx™ plus Enhancer is the optimal way to perform viability PCR on gram-negative bacteria. PMA Enhancer is available as a stand-alone product, and is also a component of our PMA Bacterial Viability Kits (gram-negative strains only) (see below).

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.

PMA Enhancer for Gram-Negative Bacteria

Product NameCatalog No.Features
PMA Enhancer for Gram Negative Bacteria, 5X Solution31038•    Improves live/dead discrimination in gram-negative strains

Back to top


PHOTOACTIVATION DEVICES


PMA-Lite™
The PMA-Lite™ LED photolysis device allows for time- and temperature-controlled light treatment of PMAxx- or PMA-treated samples in microcentrifuge tubes.

PMA-Lite™ Features:

  • Provides even illumination to up to 18 microcentrifuge tubes
  • Internal fan keeps temperature < 37°C
  • Four timer settings for 10, 15, 20 or 30 minutes of light exposure
  • Durable LED lights with 465-475 nm emission
  • For efficient activation of PMAxx™, PMA, EMA, or similar dyes

Glo-Plate™ Blue
The Glo-Plate™ Blue LED Illuminator is designed for even light treatment of PMAxx™- or PMA-treated samples in plates or larger tubes.

Glo-Plate™ Blue Features:

  • Provides even illumination across a flat surface, ideal for multi-well plates
  • Four timer settings for 10, 15, 20 or 30 minutes of light exposure
  • Durable LED lights with blue emission
  • Light exposure surface stays cool
  • For use with of PMAxx™, PMA, or Biotium’s DNAzure® Visible Gel Stain

PMA-Lite LED Photolysis Device
PMA-Lite™ LED photolysis device
Glo-Plate™ Blue LED Illuminator

Photoactivation Devices

Product NameCatalog No.Features
PMA-Lite™ LED Photolysis DeviceE90002•    Photoactivation device, holds 16 microcentrifuge tubes
Glo-Plate™ Blue LED IlluminatorE90004•    Photoactivation device for plates or larger tubes

Back to top


STRAIN-SPECIFIC V-PCR KITS


Strain-specific v-PCR kits are designed for selective detection of viable bacteria from a specific strain using PMAxx or PMA dye and real-time PCR. The kits contain PMA dye OR PMAxx™ dye, Forget-Me-Not™ qPCR Master Mix, and validated PCR primers for detection of selected strains of bacteria that are of widespread interest to food safety, public health, and/or antibacterial research.

Don’t see your favorite bug? Let us know at techsupport@biotium.com

Kits include:

• PMA dye OR PMAxx dye
• Forget-Me-Not qPCR Master Mix
• ROX reference dye
• PMA Enhancer (gram-negative strains only)
• Validated PCR primers for specific bacterial strain

PMA Real-Time PCR Bacterial Viability Kits are available for:

Salmonella enterica
Mycobacterium tuberculosis
Staphylococcus aureus
Staphylococcus aureus (methicillin-resistant)
Listeria monocytogenes
E. coli
E. coli O157:H7
Legionella pneumophila

Product NameSKUBacteria StrainGene NameSizePurchase
PMA Real-Time PCR Bacterial Viability Kit – E. coli (uidA)31050E. coliuidA200 assaysPurchase 31050
PMA Real-Time PCR Bacterial Viability Kit – E. coli O157:H7 (Z3276)31037E. coli O157:H7Z3276200 assaysPurchase 31037
PMA Real-Time PCR Bacterial Viability Kit – Listeria monocytogenes (hly)31051Listeria monocytogeneshly200 assaysPurchase 31051
PMA Real-Time PCR Bacterial Viability Kit – Salmonella enterica (invA)31033Salmonella entericainvA200 assaysPurchase 31033
PMAxx™ Real-Time PCR Bacterial Viability Kit – E. coli (uidA)31050-XE. coliuidA200 assaysPurchase 31050-X
PMAxx™ Real-Time PCR Bacterial Viability Kit – E. coli O157:H7 (Z3276)31037-XE. coli O157:H7Z3276200 assaysPurchase 31037-X
PMAxx™ Real-Time PCR Bacterial Viability Kit – Listeria monocytogenes (hly)31051-XListeria monocytogeneshly200 assaysPurchase 31051-X
PMAxx™ Real-Time PCR Bacterial Viability Kit – Salmonella enterica (invA)31033-XSalmonella entericainvA200 assaysPurchase 31033-X
PMA Real-Time PCR Bacterial Viability Kit – Legionella pneumophila (mip)31053Legionella pneumophilamip200 assaysPurchase 31053
PMA Real-Time PCR Bacterial Viability Kit – Mycobacterium tuberculosis (groEL2)31034Mycobacterium tuberculosisgroEL2200 assaysPurchase 31034
PMA Real-Time PCR Bacterial Viability Kit – Staphylococcus aureus (mecA)31036Staphylococcus aureusmecA200 assaysPurchase 31036
PMA Real-Time PCR Bacterial Viability Kit – Staphylococcus aureus (nuc)31035Staphylococcus aureusnuc200 assaysPurchase 31035

 

Back to top


PMA Dye, 20 mM in H2O

From: $121 Sizes: 100 uLCatalog #: 40019

PMA Enhancer for Gram Negative Bacteria, 5X Solution

From: $74 Sizes: 16 mLCatalog #: 31038

Glo-Plate Blue LED Illuminator

From: $600 Sizes: EachCatalog #: E90004

PMA Real-Time PCR Bacterial Viability Kit – Listeria monocytogenes (hly)

From: $315 Sizes: 200 assaysCatalog #: 31051, - 31051-XView allHide

PMAxx, 20 mM in H2O

From: $121 Sizes: 100 uLCatalog #: 40069

PMA-Lite LED Photolysis Device

From: $1,943 Sizes: EachCatalog #: E90002

PMA Real-Time PCR Bacterial Viability Kit – E. coli O157:H7 (Z3276)

From: $315 Sizes: 200 assaysCatalog #: 31037, - 31037-XView allHide