Low-cost metaphase finder system.

In counting chromosome aberrations at low-dose radiation exposure in biological dosimetry, an automation technique has been required to process a large number of sample preparations. The metaphase finder is an automated optical microscope system, which automatically scans and finds metaphase cells on the slide glass in low magnification and relocates metaphase cells to the center of the field of view of the microscope to observe chromosomes in high magnification. The authors have constructed a cost-effective metaphase finder system by assembling commercially-available components, such as microscopes, motorized sample stages, personal computers and general-purpose image analysis software, instead of purchasing one dedicated system. The new system has high cost-effectiveness and high flexibility in adapting to the new staining methods. Mathematical morphology-based image processing to the algorithm was used to find metaphase cells. In particular, the morphology for the gray-image was used for the newest version. The performance of this metaphase finder system was tested. The new machines were distributed to six institutes of the Chromosome Network for Biodosimetry in Japan for testing the new algorithm for practical use. The scanning speed was 14.5 to 18.1 min cm2. The system was slower than several commercial metaphase finders, but there were few false positives. This system is economical and satisfactory for practical use.