Method of scanning and referencing the two-dimensional position within a drawer of at least one cassette for storing tissue and cellular samples, in the medical field, said drawer comprising compartments distributed in columns and rows , in which: - positioning at least one cassette inserted with the upper surface facing upwards within a compartment of said drawer ; - automatically performing, during a first pass, a systematic scanning of all the compartments by checking the presence of a cassette within each of said compartments , the scanning being optical and consistent in moving automatically and relatively to the top of said drawer along at least one trajectory passing over all the compartments by the scanning and reading means comprising an optical foccal bead emitting a light beam, in particular a laser beam, making it possible to measure the distance between its point of emission and the point of reflection, and a light scanner ; - in the event of detection of the presence of a cassette within its compartment , a reading is performed, by the light scanner , of data present on said upper surface and said cassette is identified; - the two-dimensional position of said cassette as identified by means of the coordinates of its compartment , according to its column and its row , is referenced and recorded. - in the event of a reading error by the light scanner, the position where the reading error was observed is recorded, characterized in that : - in the event of a reading error during a first pass, the detection and reading means are moved directly to the position where the observed error occurred and was previously recorded, without performing a new scanning and/or reading of all the other compartments where these operations have previously properly taken place during the first pass, and the scanning is repeated directly at the location where the error occurred, thus refraining from performing the entire first pass again and scanning the entire drawer. - positioning at least one cassette inserted with the upper surface facing upwards within a compartment of said drawer ; - automatically performing, during a first pass, a systematic scanning of all the compartments by checking the presence of a cassette within each of said compartments , the scanning being optical and consistent in moving automatically and relatively to the top of said drawer along at least one trajectory passing over all the compartments by the scanning and reading means comprising an optical foccal bead emitting a light beam, in particular a laser beam, making it possible to measure the distance between its point of emission and the point of reflection, and a light scanner ; - in the event of detection of the presence of a cassette within its compartment , a reading is performed, by the light scanner , of data present on said upper surface and said cassette is identified; - the two-dimensional position of said cassette as identified by means of the coordinates of its compartment , according to its column and its row , is referenced and recorded. - in the event of a reading error by the light scanner, the position where the reading error was observed is recorded, - in the event of a reading error during a first pass, the detection and reading means are moved directly to the position where the observed error occurred and was previously recorded, without performing a new scanning and/or reading of all the other compartments where these operations have previously properly taken place during the first pass, and the scanning is repeated directly at the location where the error occurred, thus refraining from performing the entire first pass again and scanning the entire drawer. <EOS>