Storage conditions for most stock solutions have already been pointed out; however, some
additional points can be made. For convenience, many labs prepare stock solutions and then
divide them into aliquots sufficient to prepare from 1 to 10 liter of medium; these aliquots are
stored in small vials or plastic bags in a freezer. This procedure removes the inconvenience of
having to un-thaw a large volume of frozen stock each time medium is prepared. Some have
found that heating in a microwave oven is a satisfactory and quick method of thawing
concentrated medium.