SYSTEM FOR FLUORESCENCE METAPHASE FINDING AND SCORING OF CHROMOSOMAL TRANSLOCATIONS VISUALIZED BY IN-SITU HYBRIDIZATION

Full automation on the scoring of radiation-induced chromosomal aberra tions in conventionally stained metaphase spreads cannot be achieved r eliably due to the complex image analysis problems involved. More succ ess may be obtained by using in situ hybridization staining of the chr omosomes. We describe the development of a system to detect metaphases on the basis of a fluorescent counterstain and subsequently analyze t he number of translocations with the aid of whole chromosome paints fl uorescing in a different colour. The system consists of a Macintosh II fx computer, an automated Ergolux microscope equipped for fluorescence , and a Sony CCD camera. The performance of the metaphase finder was m easured on a small set of slides counterstained with DAPI, whereas the suitability of the system for scoring aberrations was tested in a sma ll feasibility study for the detection or radiation-induced translocat ions involving chromosome 4. The potentialities of the system for the use of multiple colours are discussed.