AUTOMATED METAPHASE FINDING - AN ASSESSMENT OF THE EFFICIENCY OF THE METAFER2 SYSTEM IN A ROUTINE MUTAGENICITY ASSAY

The efficiency of the automated metaphase finding system METAFER2 is a ssessed in a routine mutagenicity assay using an aneuploid rat liver c ell line treated with various promutagens. Data sets generated by auto mated and manual selection of metaphases are compared. It is demonstra ted that METAFER2 routinely allows an efficient automatic identificati on of metaphases not only in lymphocyte preparations, but also in prep arations from mammalian cell lines with varying chromosome numbers. Al though larger slide areas are required for automated compared to manua l metaphase scanning, the automatic system is faster by a factor of ab out 5. The interactive visual elimination of metaphases of insufficien t quality is an easy and fast procedure. METAFER2 allows an unbiased s election of metaphases irrespective of their appearance as homogeneous ly stained first or harlequin-stained second division cells. Random se lection of metaphases is neither influenced by various structural chro mosome changes nor by increased frequencies of sister-chromatid exchan ges.