sample holder 30 in the longitudinal direction of the ridge 23 is not fixed this can not lead to mutual movement because the friction occurring as a result of the clamping prevents such movement it should be noted that embodiments are also possible whereby the ridge is made in the sample holder 30 and the groove is made in the sample carrier 20 fig5 schematically shows a coupling tool and a sample carrier according to the invention the coupling tool 50 consists of a resilient body 51 with two jaws 53 and 54 and a stop 52 the sample carrier 20 with sample 1 can be slid into the coupling tool as shown normally the coupling tool will be somewhat open in such a manner that the distance 55 between the jaws 53 and 54 of the coupling tool is greater than the height 27 of the sample carrier 20 in non depressed state by now pushing the jaws 53 and 54 toward one another the sample carrier located in the coupling tool is depressed the stop 52 limits the maximal amount by which the coupling tool is depressed the maximal amount of depression is such that the height 27 is limited by the stop 52 at a height that is a little smaller than the height 33 of the sample holder 30 in this manner it is possible to depress the sample carrier 20 in such a way that it can be inserted into the sample holder 30 without touching the latter the jaws 53.