Metaphase quality can be monitored by automatic counting of bands

A high quality of cytogenetic preparations is important for maintaining a high standard in the cytogenetic laboratory. In the past, quality has been assessed by visual counting or estimation of the number of bands on chromosomes. In this paper we have counted bands automatically during karyotyping by using the Magiscan chromosome analysis system. A high correlation between automatic and visual counting was found, the automatic counting was reproducible and count figures were comparable when the karyotyping machines were operated by different technicians. The automatic counting procedure has now been included in our routine for 1 year. The highest numbers of bands were counted on slides from peripheral blood, with fewer bands for amniotic fluid and the lowest number for cells from chorionic villi. All three cell types showed significant variations in band number over time, which may be due to changes in weather conditions and/or the reagents used for cell culture, harvest and staining. It is concluded that the automatic counting procedure may be used to monitor the quality of metaphases over time and to set limits for band number on routine preparations acceptable for analysis.