Retrospective biological dosimetry by FISH

This chapter reviews the present status of applying fluorescence in situ hybridisation (FISH) for retrospective biological dosimetry by chromosomal analysis. The technique helps to overcome a major drawback, the limited persistence of signal, of the more traditional method of dicentric analysis. FISH enables the more persistent so-called stable translocations to be visualised. Criteria developed by a consensus of European laboratories are described. They attempt to define which cells and which types of translocations to score for both in vitro calibration and case investigation. Also reviewed are the control levels of translocations which are highly age dependent and constitute the major determinant of the low-dose sensitivity of the method. Evidence for the stability of the technique with time is discussed. This needs further verification by following up new accident cases for many years.