A containment cylinder was a type of cylindrical-shaped container used for collecting or holding samples.
Oxygen aboard 22nd century shuttlepods was kept in O2 cylinders. (ENT: "Shuttlepod One")
In 2369, Lursa and B'Etor traded a cylinder of bilitrium in exchange for thirteen kilograms of latinum. (DS9: "Past Prologue")
The Harvesters were stored in cylinders. (DS9: "Armageddon Game")
In 2371, a biopolymer sample was contained in a cylinder aboard Voyager. (VOY: "Emanations")
Neelix owned a containment cylinder, which he called a little wonder. He once almost lost it to the Kazon. In 2374, it was stored in a Voyager cargo bay, where he retrieved it planning to contain a small amount of protomatter in it. (VOY: "Mortal Coil")