The automatic program for cytogenetic investigations of differentially stained chromosomes was developed and used in practice. The high sensitive criterium for automatic selection of persons who has the early symptoms of karyotype instability was created. We performed the cytogenetic analysis in the women who has a burdened obstetric anamnesis after the exposure to radiation in Pripyat, in the group of healthy women from Kiev, and began the creation of computerized data bank of differentially stained human chromosomes.