Abstract: A ring of cells for analytical devices operating on the centrifugal principle and photometrically measuring a sample for analysis, the system comprising a number of individual cells disposed in a circle and made of thermoplastics, each cell having three interconnected chambers, i.e. a sample chamber, a reagent chamber and a photometric measuring chamber, the major axes of the sample chamber and the reagent chamber being at right angles to the plane of rotation and the major axis of the measuring chamber coinciding with the plane of rotation. In order to simplify and thus reduce the cost of the ring of cells, each cell at its upper edge has a laterally projecting tongue which completely or partly overlaps the adjacent cell and is secured thereto. It is particularly advantageous to use the above ring of cells in a centrifugal analyzer for clinical chemistry.