The Dose—response for Low-LET Radiation-induced DNA Double-strand Breakage: Methods of Measurement and Implications for Radiation Action Models

Summary

There is considerable controversy over the form of the dose—response for DNA double-strand breakage (dsb) induction in mammalian cells by low-LET type radiation. This controversy centres on the techniques used for measuring DNA dsb. The applications and shortcomings of the four major techniques for estimating DNA size—sedimentation, viscoelastometry, electrophoresis, and non-denaturing filter elution—are examined. In particular, the criticisms of the results obtained using the non-denaturing filter elution technique, which have suggested that the DNA dsb dose—response is non-linear, are discussed. It is concluded that these results may require a re-evaluation of the basic assumptions of many radiation action models.