Monthly reports generated by the Wellcome Trust Clinical Research Facility Genetics Core at the Western General Hospital Edinburgh, containing up-to-date information for blood work performed on LBC1936 samples, including LBC number, name, date of birth, and date of attendance, were checked against records to ensure consistency and discrepancies were verified and forwarded to the Genetics Core for amendment. The results of DNA sex-typing analysis, performed by the Genetics Core for all samples, were cross-matched to the LBC1936 databases to confirm that correct labelling of samples had taken place. This revealed several errors, four of which were caused by mixing-up of pairs of blood tubes at the extraction or labelling stage. These were rectified by re-analysis or the provision of a second sample from those participants.
