A system for automatic location of metaphase chromosomes was designed, implemented, and evaluated. Detection criteria were optimized for different chromosome preparations, and signal features were measured for each detected object. Discriminant function analysis was performed on data from a large number of slides in order to distinguish between debris and metaphases. It was found that discrimination between interphase nuclei and metaphases is relatively simple and can be accomplished at the level of detection, whereas debris presents a problem at the low magnification used. Nevertheless, in the case where debris was most abundant, the overall classification accuracy was over 80%.ETX