The invention relates to the field of integrated systems which comprise a test element and a lancet which can be firstly used to make a wound in a skin opening in order to collect a sample. The sample is subsequently directly taken up by the test element in the process of which it comes into contact with a reagent contained in the test element and results in an optically detectable change in a test field. The change in the test field is detected by means of an analytical unit which is optically contacted with the test field via at least one light-conducting element.
