Hello: Has anyone tried the StrataCooler Cryo Preservation Module from Stratagene for freezing worm strains? I have been using the Nalgene "Mr. Frosty", and the Stratacooler looks like it could subsitute without the necessity for continual replenishment with isopropanol. If you've had any experience with this product, I'd appreciate hearing about it. Thanks, Fern -- ---