The effect of semen processing on sperm DNA integrity: comparison of two techniques using the novel Toluidine Blue Assay

ObjectiveThe first goal of this study was to determine the effect that semen processing has on sperm DNA integrity. The second goal was to assess which processing technique (modified swim-up versus density gradient centrifugation) results in a superior sample. DNA integrity was measured using a novel Toluidine Blue Assay.Study designSide-by-side comparison.Materials and methodsRaw semen samples were collected from thirty-two male individuals and scored for routine semen analysis. Prior to discarding the specimens identical aliquots were divided and processed by density gradient centrifugation and a modified swim-up technique. The Toluidine Blue Assay was used to analyze raw and processed samples.ResultsBoth density gradient centrifugation and the modified swim-up improved DNA quality compared to the unprocessed sample. However, the modified swim-up technique proved superior.ConclusionsThe swim-up technique generates a sperm sample with better DNA integrity. Should DNA integrity correlate with better pregnancy rates in IUI and IVF, respectively, the swim-up may be the sperm processing technique of choice for these procedures.