A system (100) and a method for the unequivocal allocation of histological cassettes (30) and specimen slides (60) is described. The system encompasses a microtome (1) and at least one reading unit (80). The data (33) of the histological cassette (30) and the data (33) of the at least one specimen slide (60) are read by means of the reading unit (80). The reading unit (80) is provided with at least one indicating element (83) that outputs a signal in accordance with the degree of correspondence between the data (33) of the histological cassette (30) and the data (33) on the specimen slide (60).