Apparatus for treating tissue specimens comprises a stationary outer casing (2) in the top of which is positioned an annular trough (3) for holding a liquid. Rotatably mounted in the outer casing (2) is a central hub (5) supporting a disc-like lid (6) the underside of which carries a magnet (7). In use, the magnets hold, in a detachable manner, tissue specimens (12) and the trough (3) is filled with a liquid for treating the specimens. The hub (5) is capable of vertical translational movement with respect to the casing (2) to enable the specimens to be lowered into and subsequently lifted out of the trough (3). A method of treating tissue specimens is also provided.