The use of centromeric/telomeric PNA probes in prematurely condensed chromosomes of peripheral blood lymphocytes for absorbed dose estimation

Abstract

Background: The frequency of dicentric chromosomes in human peripheral blood lymphocytes at metaphase is considered as the “gold-standard” for biological dosimetry and at present is the most widely used method for dose assessment. This methodology requires lymphocyte culture and analysis time of more than three days. Such long time period, is inadequate in radiation emergency medicine since a rapid and accurate estimation of the dose is considered to be a high priority. Alternatively, cell fusion mediated premature chromosome condensation (PCC) enables the observation of radiation-induced cytogenetic damage directly in non-stimulated lymphocytes without the need of blood culturing. Quantification of an exposure by means of this method has been limited so far mainly to the analysis of chromosome fragments and rings. This limitation is due to the fact that staining with Giemsa of prematurely condensed chromosomes (PCCs) does not allow visualization of the centromeric regions and, consequently, the identification of dicentrics, centric rings, and acentric fragments. In the present work, we overcome this shortcoming by developing a methodology enabling us the detection of dicentric chromosomes rapidly and accurately in non-stimulated lymphocyte PCCs.