A method and cartridge for determining an amount of at least two analytes in a biological sample and an automatic analyzer are disclosed. The cartridge may comprise a cartridge inlet, a sample holding chamber fluidically connected to the inlet, and two or more metering chambers. Each metering chamber may comprise a sample inlet, a sample outlet, and a metered outlet for dispensing a predetermined volume. At least one sample distribution channel is connected between the sample outlet of a metering chamber with a sample inlet of another metering chamber. For each metering chamber, a connecting tube fluidically connects the sample inlet with the sample holding chamber, a microfluidic structure for processing the sample into a processed sample connects to the sample outlet, and a measurement structure fluidically connects to the microfluidic structure and enables measurement of the processed sample to determine the amount of the analyte in the processed sample.