Purpose : To investigate three areas: the staining of spermatozoa; the Computer Assisted Semen Analysis (CASA); and the variability of technicians.
Methods : Staining experiment: sperm from 15 beef bulls were randomized to one of three staining protocols. CASA experiment: slides were evaluated using the Integrated Visual Optical System and compared to technician results. Variability of technicians: five laboratorians analyzed the same set of 20 slides six different times.
Results : Staining experiment: the size of the sperm increased in proportion to increased time and heat associated with each successive protocol. CASA experiment: coefficient of variation ranged from 18.3 to 101.7% (12 slides). Variability of technicians: the mean sperm morphology results ranged from 7.3 to 15% normal forms.
Conclusions : Until laboratories adhere to the universal standard set by the World Health Organization to evaluate sperm morphology, a laboratory must rely on its own quality control to insure repeatable results.