THE DESIGN, OPERATION AND EVALUATION OF A HIGH SPEED AUTOMATIC METAPHASE FINDER

An automatic television microscope coupled to a PDP 9 computer is described which detects metaphase cells on slides stained by one of several generally used staining procedures. It determines the presence of a candidate cell by the number of chromosomes on a first pass. On a second pass it selects suitable cells by the size, eccentricity and radius of gyration of the distribution of the events. The finding speed is about 1 cm 2 /min for the first pass and about 6 sec/cell selected. The quality of the cells selected was checked by cytogeneticists in two laboratories. Depending on the criteria used, 10-50% of the cells selected were found to be of good quality, useful for manual or machine analysis. It was concluded that a finder of this performance could substantially advance the practice of manual chromosome analysis and would be essential for computerized systems of rapid karyotyping.