Cuvette, comprising at least one measuring area on each one of two arms that are pivotally connected to each other such that from a swung-apart condition, they can be swung together into a measuring position in which the two measuring areas have a distance for positioning a sample between the measuring areas, and means for positioning the two arms in a measuring position in a cuvette shaft of an optical measuring device with a sample between the two measuring areas in a beam path of the optical measuring device that crosses the cuvette shaft.