The use of latex beads in external quality assurance and internal quality control for routine semen analysis.

The usefulness of latex beads of defined concentration was assessed as a substitute for sperm in the performance of External Quality Assurance (EQA) and Internal Quality Control (IQC) of semen analysis. Within the EQA programme, mean±SEM bias (%) was significantly reduced in 2007 compared to 2002 for both specialist (6.0%±5.4% vs. 55.0%±5.9%) and non-specialist (18.4%±5.9% vs. 90.9%±13.4%) laboratories (both p<0.0001), indicating improved accuracy over time. Within the IQC programme, the beads were used in the appraisal of two scientists, one experienced and one inexperienced, against a known standard. Beads were also used to calibrate eleven counting chambers, resulting in one old chamber being discarded due to its poor performance. The present study has shown that the use of a defined concentration of beads is an excellent adjunct to IQC and EQA programmes enabling the performance of both people and equipment to be assessed in an objective manner.