radiation dosimetry model DoseEstimate/CABAS DoseEstimate and CABAS (Chromosomal Aberration Biodosimetry Analysis Software) are freely available PC software tools for fitting calibration curves in chromosome aberration biodosimetry, enabling estimation of radiation doses from cytogenetic data (dicentric chromosomes, translocations) following radiological accidents or incidents. They incorporate Poisson statistics for overdispersion analysis and are used internationally in biodosimetry laboratories as standard tools for dose assessment from biological samples. Both are available free on request from the authors. Located at PHE/SU. Deperas J. et al., Radiat. Prot. Dosim. 2007 124:115-23 Paul Schofield