These react chemically to form other radicals or hydrogen peroxide. These mutations can be in somatic tissue, and induce cancer, or take place in a germ cell, and be transmitted from generation to generation. As a mutagen, radiation increases the frequency of chromosome aberrations and other mutational events. At the molecular level, radiation induces DNA damage, including strand breaks and base deletions. At the chromosomal level, radiation may produce breaks that result in deletions, translocations, and chromosome fragments.
Radiation can also induce aneuploidy through chromosome loss.
The Ames test is a bioassay developed by Bruce Ames and colleagues for identifying mutagenic compounds. The test can be used to rapidly screen chemicals for their capacity to cause mutations. The procedure uses four tester strains of the bacterium Salmonella typhimurium that were genetically constructed for use in mutagensis screening. One strain is used to detect base pair substitutions, and the other three detect frameshift mutations. All four strains require the amino acid histidine for growth.