A method is given for the production of a jelly, consisting of a mixture of formaldehyde solution and agar-agar gel, which can be used to safely transport and store medusae and other gelatinous organisms. The jelly slows down the movements in the medium, keeps the medusae separated from each other and prevents the sinking of the organisms to the bottom of the container. The jelly also appears to be a good long term preservation medium.