The use of peripheral blood mononuclear cell prematurely condensed chromosomes for biological dosimetry.

Even though the premature chromosome condensation (PCC) technique has been shown to be a powerful cytogenetic tool, it has not yet been applied for biological dosimetry purposes. An improved and simple methodology for polyethylene glycol-mediated cell fusion and PCC induction has given the opportunity to explore the use of peripheral blood mononuclear cell prematurely condensed chromosomes as a biological dosimeter of absorbed radiation dose. This new approach offers several advantages, and it is presented as an alternative to the conventional cytogenetic technique. First, the chromosomal damage may be visualized in about 2 hr from the moment a blood sample is available. Consequently, the chances for interphase cell death or chromosomal repair are decreased. Second, the amount of blood required is only 0.5 ml. Third, the PCC analysis of about 100 mononuclear blood cells shows the radiation damage even at low doses, whereas hundreds of lymphocyte metaphases must be analyzed when conventional cytogenetic techniques are applied. Fourth, the linear dose-response relationships obtained may be easily standardized. The methodology used diminishes the possibility of differential results from one laboratory to another by avoiding the variables introduced by the stimulation and culture of lymphocytes required by conventional cytogenetic techniques. Finally, the kinetics of lymphocyte chromosome aberration recovery can be directly examined. This approach provides us, therefore, with a direct and more sensitive method for the estimation of radiation injury and repair.