PMA Enhancer for Gram Negative Bacteria was designed to improve PMA- and PMAxx™-mediated discrimination between live and dead gram-negative bacteria. PMA Enhancer is provided as a 5X solution, and is added to a sample before the addition of 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. Thus, PMA or PMAxx™ plus Enhancer is the optimal way to perform viability PCR on 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. The product comes with 16 ml of 5X PMA Enhancer for Gram Negative Bacteria solution.