CellROX Green dye diluted in a DMSO stock solution is stable for multiple freeze-thaw cycles, but it is not stable long-term in aqueous solution. Please note, every time the stock solution is opened, some of the dye can oxidize, which will increase background noise. DMSO readily absorbs moisture from the air, especially when cold, so be sure to completely thaw the stock solution to room temperature before opening and only open briefly. Water in the DMSO will gradually cause the dye to precipitate and come out of solution. Minimize the number of times you use a stock solution to several freeze-thaw cycles or make small aliquots to reduce the number of freeze-thaw cycles.
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