Comparison of four mechanical methods to retrieve spermatozoa from testicular tissue

To maximize the total number of spermatozoa which can be retrievedfrom a testicular biopsy, four mechanical methods for preparationwere compared. In all, 17 biopsies were divided into four equalfractions, which were weighed individually and prepared by roughshredding (control), fine mincing, vortexing and crushing (electricalPotter). After resuspension in an erythrocyte-lysing buffer,removal of the remaining tissue pieces, washing and centrifugation,the following parameters were evaluated: number of spermatozoaper 100 mg tissue, percentage motility, percentage vitalityand percentage normal morphology (strict Kruger criteria). Afterfurther purification by discontinuous Percoll centrifugation,the same parameters were assessed again. This procedure wasefficient in obtaining only spermatozoa in the final fraction.Before Percoll centrifugation, only minor differences betweenmethods were observed. Percoll centrifugation generally resultedin a pronounced loss of sperm cells, partly because of the abnormaldimensions of the eliminated cells. After Percoll centrifugation,treatment of the testicular tissue by fine mincing was the mosteffective method in terms of the total number of motile spermatozoaand percentage normal morphology.