Support

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

Ethidium monoazide, bromide (EMA)

Ethidium monoazide bromide is a fluorescent nucleic acid binding dye. The dye, after photolysis, binds covalently to nucleic acids. It can be used for viability PCR.

Ethidium monoazide, bromide (EMA)
SPECIAL OFFER

Order 5 or more and receive 10% off.

Catalog #

40015

CAS number

58880-05-0

Size

5 mg

Size
Catalog #
price
Qty
5 mg
Clear selection
Add to wishlist
ADD TO CART
(Please select quantity above )

Wishlist updated! View wishlist

Shipping & Tax (CA only) not included in price. Learn more

Taxes: Tax is assessed in the state of California and is calculated during checkout based on your shipping information. Shipment Method: Shipping and handling methods will be assessed and calculated at time of shipment based upon item(s) storage temperature conditions. Expedited shipment may be requested at time of checkout.


Request a Bulk Quote

Product Description

Ethidium monoazide bromide (EMA) is a fluorescent nucleic acid stain with a photoaffinity label. The dye, after photolysis, binds covalently to nucleic acids.The dye has been used to footprint drug binding sites on DNA2, to modify plasmid DNA,3,4 and for labeling yeast cells for leukocyte phagocytosis assays5. A particularly useful application of the dye is to label dead cells in a mixed population of live and dead cells. Because EMA is relatively impermeant to live cells, it selectively binds DNA in dead cells. Photolysis renders the dead cell DNA covalently labeled with the dye. One can then wash and fix the cell preparation for analysis by microscopy, fluorescence plate reader or flow cytometry. The major advantage of this method is that researchers can avoid extensive manipulation of live pathogenic organisms.7

EMA has been used to differentiate between viable and dead bacteria by 5′-nuclease PCR.8

For viability PCR applications, Biotium also offers propidium monoazide iodide (PMA, catalog numbers 40013 and 40019) as well as our new and improved viability PCR dye, PMAxx™ (catalog number 40069). PMA and PMAxx™ are less membrane permeant than EMA and therefore more selective for dead cell labeling for qPCR quantitation of viable bacteria.9

For photoactivation of PMA, PMAxx™ or EMA dye, we recommend the use of Biotium’s PMA-Lite™ LED Photolysis Device (E90002), which is designed to conduct photolysis under controlled conditions.

    • Ex (pH 3) = 458 nm
    • λExEm (after photocrosslinking to nucleic acid) = 510/600 nm6
    • Orange solid soluble in DMF, or ethanol
    • Store desiccated at 4oC or -20oC and protect from light, especially in solution
    • C21H18BrN5
    • MW: 420
    • [58880-05-0]

References

1. J Mol Biol 92, 319 (1975).

2. Euro J Biochem 182, 437 (1989).

3. J Biol Chem 257, 13205 (1982).

4. J Biol Chem 259, 11090 (1984);.

5. Cytometry 11, 610 (1990).

6. For excitation and emission of the dye before and after binding to DNA/RNA and photolysis, please see Nucleic Acids Res.5, 4891 (1978).

7. Cytometry, 12, 133 (1991).

8. Biotechniques, 34, 804 (2003)

9. J. Microb. Meth., 67, 310 (2006).

 

You may also like…

Support & Faq

PMA and PMAxx™ for viability PCR

Biotium offers the PMA-Lite™ LED Photolysis Device for light-induced cross-linking of PMAxx™ and PMA to dsDNA. The PMA-Lite™ is designed for samples in microcentrifuge tubes.

For users that have samples in a different format (for example, 96-well plates or filters), we will soon be releasing a new light box that will allow for greater flexibility of assay format.

Commercial halogen lamps (>600 W) for home use have been employed for photoactivating PMA in some publications, though results have not been consistent due to inevitable variation in the set-up configurations. If you decide to use a halogen lamp, we recommend that you lay tubes on a block of ice set 20 cm from the light source, on a rocking platform to ensure continuous mixing. Set the lamp so that the light source is pointing directly downward onto the samples (up to 45° downward slant is OK). Expose samples to light for 5-15 min.

Category: PMA and PMAxx™ for viability PCR

← FAQs

The LEDs in PMA-Lite have brightness of 600-800 millicandela (mcd). There are three LEDs next to each tube (one bottom, two side) and the wavelength is 465-475 nm.

Category: PMA and PMAxx™ for viability PCR

← FAQs

Both PMA and PMAxx™ are both offered as 20 mM solutions in water. We also offer PMA as a solid, and customers often ask whether it needs to be dissolved in DMSO. While in some publications users have prepared their PMA stock solution in DMSO, this is not necessary. Unlike the older viability dye EMA, which is not soluble in water, PMA and PMAxx™ are very water soluble.

Category: PMA and PMAxx™ for viability PCR

← FAQs

← FAQs

Ask a question

Shipping/Shelf-life

Shipment Method: Shipping and handling methods will be assessed and calculated at time of shipment based upon item(s) storage temperature conditions. Expedited shipment may be requested at time of checkout. Please note that products with recommended storage at 4°C or -20°C may ship at ambient temperature. This will not affect product performance. When you receive the product, place it under the recommended storage conditions.