Abstract: A centrifugation device comprising a combined sample chamber and slide holder adapted to be mounted, with a microscope slide (26), in a centrifuge in a predetermined position, after placing a fluid biological sample containing cells in the sample chamber. The device comprises an integrally moulded body (10) affording a base (14) which engages the microscope slide, and also affording a back plate (14) connected with the base plate by an integral hinge (22) a latch mechanism formed integrally with the remainder of the device is arranged, when the back plate (14) is closed against the rear of a microscope slide (26) engaged with the base (14), to locate the slide between the base and the back plate and to hold the back plate in this closed position until fracture of a retaining element from the integrally moulded body. Thus the device can be used once only.