Spectrophotometric Quantitation of Mammalian Spermatozoon Motility I. Human

Human sperm motility has been spectrophotometrically quantitated by a technique based upon the optical anisotropic properties of motile sperm. A sperm motility index was determined and controlled experiments showed that the index (SMI) was positively correlated to the percent of progressively motile cells (r=0.92) and negatively correlated to the percent of heat killed cells in the sample (r=−0.92). In a single dilution of sperm cells with aliquots studied at selected time intervals for 90 min, the index correlated with a decline in the progressive motility (r=0.95). The correlation between the index and the percent progressive motility in the fresh dilution was r=0.86. When the index was determined on the same original population of spermatozoa, but experimentally prepared with different concentrations of cells, the index was independent of final cell numbers in a range of 2.5–14.3 × 106 cells/ml. Semen analyses were performed on each ejaculate and a correlation between the SMI and progressive motility (r=0.85) was observed.