Technical report: application of the Metafer2 fluorescence scanning systemfor the analysis of radiation-induced chromosome aberrations measured by FISH-chromosome painting

The Metafer2 fluorescence scanning system was used for routine analysis of radiation-induced exchange aberrations measured by fluorescence in situ hyb ridisation (FISH) chromosome painting in human peripheral lymphocytes. The system enables a rapid and unbiased fully-automated finding and image acqui sition of fluorescently stained metaphase spreads. The chromosome aberratio n analysis is performed interactively from stored digitised processed galle ry images, presented on a screen. Appropriate software image filters are av ailable to further improve these pictures by background correction, noise r eduction and fluorescence signal enhancement. Data sets generated by computer-assisted and manual scoring of radiation-in duced reciprocal translocations (2B) and total 2B (2B + related 'one-way' t ypes) or complete dicentrics (2A) and total 2A (2A + related 'one-ways') in volving painted target chromosomes 2, 3 or 4 were compared and no significa nt differences were found. A linear-quadratic dose-response curve for total translocations (2B + 'one- ways' + complex-derived types) based on computer-assisted analysis of 27,74 1 metaphases with chromosome 4 painting was compared to a curve obtained ea rlier for manually scored translocations in a set of target chromosomes 1, 4 and 12. After extrapolation to the whole genome, no significant differenc e between both curves was found. From our results it can be derived that computer-assisted aberration analys is using the Metafer2 system is a reliable alternative to manual analysis. Since time saving for computer-assisted translocation analysis is about 50% compared to manual scoring, this system is highly promising for a practica l application in retrospective biodosimetry of human radiation exposure, (C ) 2001 Elsevier Science B.V. All rights reserved.