A number of ongoing delayed effects have now been described in the progeny of an irradiated cell. These are grouped under the rubric of radiation induced genomic instability. Perhaps the best characterized is the dynamic production of chromosomal rearrangements in some clonally expanded cells surviving irradiation. In this chapter we provide the protocols for irradiation, cell culture, chromosome analysis, and characterization of the status of genomic stability in the context of delayed radiation effects.