PROFILES OF SPERM MORPHOLOGY AND MOTILITY AFTER DISCONTINUOUS MULTIPLE-STEP PERCOLL DENSITY GRADIENT CENTRIFUGATION

Morphology and motility are important parameters for assessing the fer tilizing capacity of spermatozoa. This investigation reports a systema tic study on the profiles of these parameters after Percoll gradient c entrifugation. Spermatozoa from normal human semen were fractionated b y discontinuous Percoll gradients (30%, 45%, 75%, 90%). Spermatozoa wa shed with Earle's balanced salt solution were used as a control. After centrifugation, sperm morphology was evaluated according to strict cr iteria; motility was assessed by a computer-assisted semen analysis sy stem. The results showed that the percentage of spermatozoa with norma l morphology increased, while those with severe morphological defects decreased, as the density of Percoll increased. The percentages of mot ile spermatozoa and hyperactivated spermatozoa, and the velocity and a mplitude of lateral head displacement of the spermatozoa were signific antly higher in the 75% and 90% Percoll fractions than that in the 30% and 45% ones, and in the control. These results demonstrated that Per coll density gradient centrifugation enriched spermatozoa in terms of morphology and motility.