Microphotometry of banded human chromosomes. High resolving power by direct scanning of the specimen compared with scanning on microphotographs.

A method which was designed for microphotometric measurements of banded human chromosomes using a computer-controlled Zeiss scanning microscope photometer (SMP) is described. Modification of the Apamos 2 program (H. G. Zimmer, Zeiss, Oberkochen) enabled the scanning stage on the SMP to move the slides continuously thus obtaining high resolution of measurements. Results of scanning directly on the slides when compared with scanning on microphotographs revealed no significant differences; the banding patterns of the chromosomes were reproduced with a high degree of accuracy by both methods. Chromosomes No. 2, 10, 16, and 20 are described in detail.