Separation efficiency of a microfluidic sperm sorter to minimize sperm DNA damage

Microfluidic sperm sorters are efficient and reliable for sperm preparation for in vitro fertilization and intracytoplasmic sperm injection without damaging DNA, compared with the the centrifugation and swim-up procedure.


Kyoko Shirota, M.D., Ph.D., Fusanori Yotsumoto, M.D., Ph.D., Hiroko Itoh, M.D., Ph.D., Hirotsugu Obama, M.D., Naomi Hidaka, M.D., Ph.D., Kyoko Nakajima, B.A., Shingo Miyamoto, M.D., Ph.D.

Volume 105, Issue 2, Pages 315-321



To evaluate whether microfluidic sperm sorters (MFSSs) allow effective recovery of sorted motile sperm without DNA damage compared with the centrifugation and swim-up procedure.


Experimental laboratory study. All participants completed questionnaires regarding previous and/or current diseases, surgery, reproductive experiences, lifestyle factors, and date of the preceding ejaculation.


University research laboratory.


Male volunteers were recruited without setting conditions. Semen samples from healthy volunteers (n = 37) were collected in sterile containers by masturbation.


Flow cytometric measurement and sperm chromatin structure assay analysis of DNA damage after sperm preparation using MFSS and the centrifugation and swim-up procedure.

Main Outcome Measure(s):

Efficacy and efficiency of sperm preparation, correlation between sperm DNA fragmentation index (DFI) and semen parameters, and relationship between basic characteristics and DFI after the centrifugation and swim-up procedure.


Final sperm concentration and motility were significantly different between the centrifugation and swim-up procedure and MFSS sperm preparations. A significantly lower sperm DNA fragmentation rate was detected with MFSS compared with the centrifugation and swim-up procedure use. No correlation was observed between DFI and smoking or drinking, but significant correlations were observed between DFI and medication use and sexual abstinence duration.


MFSSs can be used to efficiently and reliably prepare sperm compared with the centrifugation and swim-up procedure. Further research on the clinical use of MFSSs is required to evaluate the safety and usefulness of this device.

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