DominoStainer is a completely automated immunostainer protected by the WO 2005/0955752 (FR 2005/00077) patent. Its advantage compared with well known high performance instruments is that DominoStainer has been developed especially for TMA slides. This stainer is appropriate for small amounts of samples in small laboratories or useful for serial tests of TMA slides. Using with reagents of Histopathology, Ltd. this instrument offers a cost-effective and environment-friendly solution. Technical advantage is the connection of the incubation chambers side by side, like the domino game. The operating software is simple, without time consuming data entry and programming. Touch screen interface ensures the operation steps and does not need additional PC or monitor. The reagent racks could be handled as separate units, the remaining reagents are reusable.