Nullentropy is a wide spread storage technology in the Dune universe. Any item may be preserved indefinitely inside a Nullentropy capsule or container.
Various Uses
In Heretics of Dune, Duncan Idaho and Miles Teg survived hidden in the No-chamber of House Harkonnen, fully stocked with provisions and weapons stored in the nullentropy system.
Later in Chapterhouse, it is revealed that the Tleilaxu Master Scytale contains a nullentropy tube of ghola cells of important persons of yesteryear, stored within his body. The cells within the apparatus are perfect and readily usable, since no time has passed within the tube.