Although highly regulated, all non-clinical toxicology studies have the potential to experience practical problems.Anticipation of potential hurdles and planning for success are key actions for all investigators to ensure a study is robust and suitable for submission and regulatory acceptance.This presentation will examine the whole study conduct process and illustrate steps you can take to the potential contamination of control samples and, in the event of an unexpected result being obtained, the procedures that must be carried out to investigate the problem.Regulatory authorities across the globe have focused on the contamination of control biological samples as a serious risk to compound development.