Due to sensitive molecular biological techniques, our understanding of chromosomal aberrations is steadily increasing. Provided here is a review of basic and applied aspects of the field. Chromosome structure, induction of DNA lesions by different clastogenic agents and their repair, induction of aberrations by agents which affect specific sequences in the DNA, and factors affecting induction and yield of chromosomal aberrations are covered. Further, topics such as automation of aberration scoring, problems associated with using chromosomal aberrations and micronuclei in population monitoring and the importance of chromosomal aberration assays in mutagenicity testing of chemicals are included.With contributions by numerous expertsDue to sensitive molecular biological techniques, our understanding of chromosomal aberrations is steadily increasing. Provided here is a review of basic and applied aspects of the field. Chromosome structure, induction of DNA lesions by different clastogenic agents and their repair, induction of aberrations by agents which affect specific sequences in the DNA, and factors affecting induction and yield of chromosomal aberrations are covered. Further, topics such as automation of aberration scoring, problems associated with using chromosomal aberrations and micronuclei in population monitoring and the importance of chromosomal aberration assays in mutagenicity testing of chemicals are included.Radiation-Induced Formation of DNA Double-Strand Breaks in Plasmids and E.coli.- UV-induced pyrimidine monoadducts and their in vivo photofootprints.- Chromatin Structure, Hyperthermia and Repair of UV-Induced DNA Photolesions in Mammalian Cells.- An Inherited Homogeneously Staining Region Derived from a Long-Range Repeat Family in the House Mouse.- Detection of Genetic Imbalances in Tumor Genomes by Fluorescence in situ Hybridization with Tumor Genomic DNA and Subregional DNA Probes.- Fluorescent in situ hybridization (FISH) in cytl3y