PromoCell supplements (SupplementMixes and SupplementPacks) are routinely shipped with dry ice. On occasion, the supplements may arrive defrosted. You can either use them immediately to prepare fresh growth media or refreeze them at -20°C. We have performed extensive stability tests and can guarantee that the supplements are stable for up to 1 week at room temperature.
Sole exception: The SupplementMix (C-39420) of our Melanocyte Growth Medium M2 is less stable and should no longer be used when it arrived thawed, at room temperature.