The first thing to note is how fixable viability dyes work. These viability dyes, like Zombie NIR, react with primary amine groups on proteins. That means that all cells will be stained with the viability dye because all cells express surface proteins. These dyes work as for viability because dead cells have permeable membranes, making the surface and intracellular proteins accessible to the viability dye and the fluorescence intensity much, much higher than live cells. Based on this information we can expect that if the manufacturer’s protocol is used (1 uL of Zombie NIR in 100 uL PBS), the Zombie NIR signature will be detected on all of the populations of cells.
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