Semiautomated chromosome analysis. A clinical test.

An interactive system for semiautomated chromosome analysis, consisting of a high-speed image processor with light-pen, TV monitor and key-board interfaced to a microscope with motorized scanning stage and video-camera and to a hard-copy printer, has been clinically tested for twenty consecutive working days. Metaphase search takes place over night. Identified metaphases are ranked automatically according to their suitability for analysis. Less than every second metaphase found cannot be either counted or analysed. 164 samples were analysed. Only one was not completed. Two numerical and two structural abnormalities were identified and clinical consequences taken. Average time per completed analysis (10 counts, four karyotypes) were 37.5 min (28-84). Average time varied between technicians. In another test including 120 metaphases and 40 karyotypes average time for counting the chromosomes of a metaphase was 37 sec. (28-48), and average time for producing one karyotype, including a hard-copy was 4 min 30 sec (3 min 43 sec-5 min 54 sec). Number of manual interactions was 8 (2-17) and 36 (25-61), respectively. Although improvements are possible, the system is able to at least double the output of four cytogenetic technicians.