title: Efficient isolation of sperm with high DNA integrity and stable chromatin packaging by a combination of density-gradient centrifugation and magnetic-activated cell sorting.
abstract: OBJECTIVE
  This study was carried out to investigate the correlations of the sperm DNA fragmentation index (DFI) with semen parameters and apoptosis, and to investigate the effects of density-gradient centrifugation (DGC) and magnetic-activated cell sorting (MACS) on reducing the proportion of sperm with DNA fragmentation and protamine deficiency.
  
  
  METHODS
  Semen analysis and a sperm DNA fragmentation assay were performed to assess the correlations between semen parameters and the DFI in 458 semen samples. Sperm with progressive motility or non-apoptosis were isolated by DGC or MACS, respectively, in 29 normozoospermic semen samples. The effects of DGC or MACS alone and of DGC and MACS combined on reducing the amount of sperm in the sample with DNA fragmentation and protamine deficiency were investigated.
  
  
  RESULTS
  The sperm DFI showed a significant correlation (r=-0.347,p<0.001) with sperm motility and morphology (r=-0.114,p<0.05) but not with other semen parameters. The DFI (11.5%±2.0%) of semen samples was significantly reduced by DGC (8.1%±4.1%) or MACS alone (7.4%±3.9%) (p<0.05). The DFI was significantly further reduced by a combination of DGC and MACS (4.1%±1.3%,p<0.05). Moreover, the combination of DGC and MACS (1.6%±1.1%,p<0.05) significantly reduced the protamine deficiency rate of semen samples compared to DGC (4.4%±3.2%) or MACS alone (3.4%±2.2%).
  
  
  CONCLUSIONS
  The combination of DGC and MACS may be an effective method to isolate high-quality sperm with progressive motility, non-apoptosis, high DNA integrity, and low protamine deficiency in clinical use.
authors.affiliation: IVF Center, Mamapapa and Baby Clinic, Ulsan, Korea.
authors.forename: Hee-Jun
authors.initials: HJ
authors.lastname: Chi
authors.affiliation: IVF Center, Mamapapa and Baby Clinic, Ulsan, Korea.
authors.forename: Su-Jin
authors.initials: SJ
authors.lastname: Kwak
authors.affiliation: IVF Center, Mamapapa and Baby Clinic, Ulsan, Korea.
authors.forename: Seok-Gi
authors.initials: SG
authors.lastname: Kim
authors.affiliation: IVF Center, Mamapapa and Baby Clinic, Ulsan, Korea.
authors.forename: Youn-Young
authors.initials: YY
authors.lastname: Kim
authors.affiliation: IVF Center, Mamapapa and Baby Clinic, Ulsan, Korea.
authors.forename: Ji-Young
authors.initials: JY
authors.lastname: Park
authors.affiliation: IVF Center, Mamapapa and Baby Clinic, Ulsan, Korea.
authors.forename: Chang-Seok
authors.initials: CS
authors.lastname: Yoo
authors.affiliation: IVF Center, Mamapapa and Baby Clinic, Ulsan, Korea.
authors.forename: Il-Hae
authors.initials: IH
authors.lastname: Park
authors.affiliation: IVF Center, Mamapapa and Baby Clinic, Ulsan, Korea.
authors.forename: Hong-Gil
authors.initials: HG
authors.lastname: Sun
authors.affiliation: IVF Center, Mamapapa and Baby Clinic, Ulsan, Korea.
authors.forename: Jae-Won
authors.initials: JW
authors.lastname: Kim
authors.affiliation: IVF Center, Mamapapa and Baby Clinic, Ulsan, Korea.
authors.forename: Kyeong-Ho
authors.initials: KH
authors.lastname: Lee
keywords: Apoptosis; Centrifugation, Density gradient; Magnetic-activated cell sorting; Protamine deficiency; Sperm DNA fragmentation index