The invention provides for a cartridge (300) for an automatic analyzer (1100), wherein the cartridge is operable for being spun around a rotational axis (102). The cartridge comprises: a fluid chamber (104) for receiving a fluid (307), an aliquoting chamber (108), a first duct (106) connecting the fluid chamber and the aliquoting chamber, a metering chamber (112) operable for causing fluid to fill the metering chamber using capillary action, and a second duct (110) connecting the metering chamber with the aliquoting chamber, wherein the second duct comprises a duct entrance (114) in the aliquoting chamber. The second duct further comprises a duct exit (116) in the metering chamber wherein the duct exit is closer to the rotational axis than the duct entrance. The second duct is operable for causing fluid to flow to the metering chamber using capillary action. The cartridge further comprises a downstream fluidic element (122) connected to the metering chamber via a valve (121) and a fluidic structure (336) for processing a biological sample into the processed biological sample. The fluidic structure comprises a measurement structure (344, 1110) for enabling measurement of the processed biological sample, wherein the fluidic structure is configured for receiving the biological sample.