A test instrument for analyzing body fluids such as blood or urine. The instrument includes a wound test tape which can be transported from a storage space into a waste space by advancing the tap. The test tape has a plurality of test sections to which body fluid can be applied at a receiving position and also includes a measuring unit for detecting a constituent of the body fluid on an active test section. In order to carry out auxiliary instrument functions, in addition to the test sections, the test tape has one or more functional sections which can be brought into a functional position by advancing the tape.