Tests of performance of four semi-automatic metaphase-finding and karyotyping systems.

Four commercially-available semi-automatic cytogenetic systems (Cytoscan, Ibas, Magiscan and Miamed) have been evaluated for both metaphase-finding and karyotyping performances, using a common set of test slides and uniform criteria. Comparisons have been made in respect of timings, number and nature of operator interactions, and false positive and negative rates. Amongst the general conclusions are the importance, for metaphase-finding performance, of a facility for ranking candidate metaphases according to their 'analysability', the need for some systems to reduce the time taken to relocate candidate metaphases, and the ability of all systems tested to detect analysable metaphases that were initially overlooked by a skilled cytogeneticist. In spite of automation, karyotyping remains a highly interactive process, strongly dependent on the skill and judgment of the operator, and therefore difficult to evaluate fully objectively.