COMPARISON OF MOTILITY CHARACTERISTICS AND NORMAL SPERM MORPHOLOGY OFHUMAN SEMEN SAMPLES SEPARATED BY PERCOLL DENSITY GRADIENT CENTRIFUGATION

The aim of this study was twofold: to investigate the ability of Perco ll gradient centrifugation (52, 68, 84%) to fractionate semen samples according to motility quality and percentage normal morphology and to determine whether there is an association between sperm motility quali ty and percentage normal morphology. Sperm motility was evaluated usin g a Hamilton Them analyzer and normal sperm morphology was manually as sessed according to the strict criteria (less than or equal to 4, 5-14 , and > 14%). The majority of motility parameters and the percentage n ormal morphology were found to be significantly improved in the 84% Pe rcoll fraction. The greatest effect was on the less than or equal to 4 % group, shifting the mean normal morphology percentage from 2.6 to 5. 2%. Curvilinear velocity (VCL) and average path velocity (VAP) were th e only two motility parameters that were significantly associated with the percentage normal morphology. Using a combined VCL,VAP vector the > 14% group was found to have a significantly different value as comp ared to the 5-14 and less than or equal to 4% groups. Percoll (discont inuous) gradient centrifugation can therefore play a significant role in the improvement of semen samples for use in assisted reproduction p rocedures. The VCL,VAP vector identified may also serve as an addition al tool in the prediction of the fertility potential of sperm samples.