Automatic detection of sister chromatid exchange

Sister chromatid exchange (SCE) is an interchange of genetic material between replication products at homologous loci. Various chemical agents or other environmental physical factors can cause SCE at concentrations insufficient to produce other significant change in chromosome morphology. A method for automatic detection of SCE is presented. By searching for the zero-crossing points in the average integrated optical density ratio, SCEs are detected and located accurately. In a preliminary experiment with 266 chromosomes, a system based on this method has achieved an accuracy of 95.5%. By monitoring and comparing the spontaneous and inductive SCE frequency, one can estimate the nature and degree of the damage the organisms suffered and appraise the short-term and long-term effects on them