Automated multiple-cell karyotyping: a clinical feasibility study.

In order to increase the efficiency of the Magiscan metaphase location and karyotyping system, its software and mode of operation have been changed. In the new multiple-cell karyotyping method, interactions by the operator are only required for relocation and counting of metaphases, but not for karyotyping. Metaphases are located and their coordinates recorded automatically as before. The first metaphase in the list is relocated, displayed on the screen, and counted by the operator. It is then karyotyped automatically while the operator relocates and counts the next metaphase in the list. This procedure continues until an appropriate number of metaphases have been counted and karyotyped. Finally a composite karyotype is printed out. Each karyotype is represented by a column of 23 chromosome pairs (1-22 and XX or XY) and all columns are lined up next to each other. Most chromosomes are correctly classified into the composite karyotype. Minor structural abnormalities are detected by comparing pairs of homologues. Overlapped, close touching, and grossly abnormal chromosomes are often misclassified or rejected and shown beneath the classified chromosomes. A trained cytotechnician can easily detect even small chromosome abnormalities on the composite karyotype. A clinical feasibility study indicates that the procedure can be used for routine cytogenetic analysis.