Computer graphics as a tool in cytogenetic research and education.

Scanning microscope photometry has been extensively used for image analysis of nuclei and chromosomes and for automated karyotyping. Color graphics terminals, software development and appropriate data manipulation have expanded the scope of scanning microphotometry so that it is now particularly useful for the quantitative analysis of cell components. We have developed application software for displaying nuclear and chromosome densities on a computer terminal of in the form of pixeled images and pseudo-three-dimensional graphic diagrams, as well as for image transformation, object illumination and rotation to enhance chromatin features. The system allowed the microphotometrical scanning of human G-, R-, C-, T-banded chromosomes and sister chromatid exchanges, the measurement of nuclear heterochromatic segments, the detection of minute chromosome structures and the distribution of high staining densities in chromosomes which are difficult to observe with simple light microscopy. The new quantitative visual information given by our interactive graphic method contributes to a better understanding of the nuclear and chromosome structure for the students engaged in cytogenetic research and teaching. The analytical perspective of computer graphics in cytogenetic research and education is briefly discussed.