Abstract: A chromatography developing chamber for developing thin layer or paper chromatographic materials comprising an elongated sleeve closed at one end, open at the other end and having a peripheral wall therebetween, such as a cylindrical sample tube. A ledge projecting inwardly from a peripheral wall of the sleeve is positioned adjacent the closed end to provide a surface for supporting the chromatographic material in the chamber. A liquid elution solvent fills the chamber from the closed end to a level below the ledge such that the chromatographic material on the ledge is supported out of contact with the solvent during a first stage of developing. The ledge permits the material to be readily displaced therefrom to fall into the solvent during a second stage of developing. The material may be displaced from the ledge by vibration, as by tapping the chamber, or by magnetic means.