Effect of measurement conditions on quantification of hyperactivated human sperm subpopulations by digital image...

The effect of different measurement conditions on the quantification of hyperactivated (HA) motility in human sperm by digital image analysis (DIA) was determined with respect to chamber depth, temperature, sperm concentration, time in the analysis chamber, culture medium, and type as well as concentration of extracellular protein components. In whole semen, the level of HA (less than 1%) as well as the values for all other motility parameters (curvilinear and straight-line velocity, linearity of forward progression, maximum and mean lateral head amplitude, and beat cross frequency) were independent (p greater than 0.05) of temperature (24 vs. 37 degrees C). In washed sperm samples prepared by in vitro fertilization procedures, the percentage of HA cells was inversely related to measurement temperature and to albumin concentration in the culture medium. The effect of temperature on percentage of HA in washed sperm was reversible. HA analysis of washed sperm from 6 donors (3 ejaculates per donor) under defined DIA assay conditions showed no intra-donor variability (p greater than 0.05) but significant inter-donor variability (donor mean percentages ranging from a low of 3.6 to a high of 28.2). These results indicate that HA is influenced by measurement conditions, that HA is donor-dependent, and that each donor shows a characteristic level of HA.