PURPOSE: To measure the yield of DNA strand breaks and clustered lesions in plasmid DNA irradiated with protons, helium nuclei, and y-rays. MATERIALS AND METHODS: Plasmid DNA was irradiated with 1.03, 19.3 and 249 MeV protons (linear energy transfer = 25.5, 2.7, and 0.39 keV microm(-1) respectively), 26 MeV helium nuclei (25.5 keV microm) and gamma-rays (137Cs or 60Co) in phosphate buffer containing 2 mM or 200 mM glycerol. Single-and double-strand breaks (SSB and DSB) were measured by gel electrophoresis, and clustered lesions containing base lesions were quantified by converting them into irreparable DSB in transformed bacteria. RESULTS: For protons, SSB yield decreased with increasing LET (linear energy transfer). The yield of DSB and all clustered lesions seemed to reach a minimum around 3 keV microm(-1). There was a higher yield of SSB, DSB and total clustered lesions for protons compared to helium nuclei at 25.5 keV microm(-1). A difference in the yields between 137Cs and 60Co gamma-rays was also observed, especially for SSB. CONCLUSION: In this work we have demonstrated the complex LET dependence of clustered-lesion yields, governed by interplay of the radical recombination and change in track structure. As expected, there was also a significant difference in clustered lesion yields between various radiation fields, having the same or similar LET values, but differing in nanometric track structure.
PURPOSE: To measure the yield of DNA strand breaks and clustered lesions in plasmid DNA irradiated with protons, helium nuclei, and y-rays. MATERIALS AND METHODS: Plasmid DNA was irradiated with 1.03, 19.3 and 249 MeV protons (linear energy transfer = 25.5, 2.7, and 0.39 keV microm(-1) respectively), 26 MeV helium nuclei (25.5 keV microm) and gamma-rays (137Cs or 60Co) in phosphate buffer containing 2 mM or 200 mM glycerol. Single-and double-strand breaks (SSB and DSB) were measured by gel electrophoresis, and clustered lesions containing base lesions were quantified by converting them into irreparable DSB in transformed bacteria. RESULTS: For protons, SSB yield decreased with increasing LET (linear energy transfer). The yield of DSB and all clustered lesions seemed to reach a minimum around 3 keV microm(-1). There was a higher yield of SSB, DSB and total clustered lesions for protons compared to helium nuclei at 25.5 keV microm(-1). A difference in the yields between 137Cs and 60Co gamma-rays was also observed, especially for SSB. CONCLUSION: In this work we have demonstrated the complex LET dependence of clustered-lesion yields, governed by interplay of the radical recombination and change in track structure. As expected, there was also a significant difference in clustered lesion yields between various radiation fields, having the same or similar LET values, but differing in nanometric track structure.
Authors: F M Milian; A N Gouveia; M R Gual; J O Echeimberg; J D T Arruda-Neto; F Garcia; A C G Schenberg; E J Vicente; O Rodriguez; F Guzman; A Deppman Journal: J Biol Phys Date: 2008-01-16 Impact factor: 1.365
Authors: Luděk Vyšín; Kateřina Pachnerová Brabcová; Václav Štěpán; Patrick Moretto-Capelle; Beatrix Bugler; Gaelle Legube; Pierre Cafarelli; Romain Casta; Jean Philippe Champeaux; Martine Sence; Martin Vlk; Richard Wagner; Jan Štursa; Václav Zach; Sebastien Incerti; Libor Juha; Marie Davídková Journal: Radiat Environ Biophys Date: 2015-05-26 Impact factor: 1.925
Authors: Brian A Sanderson; Naoko Araki; Jennifer L Lilley; Gilberto Guerrero; L Kevin Lewis Journal: Anal Biochem Date: 2014-03-14 Impact factor: 3.365