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Original Research

Open Access

Elimination of bacteria from semen using a combination of density gradient centrifugation and swim-up

  • Zhiheng Chen1,†,
  • Lingxiao Jiang2,†,
  • Hui Wang11
  • Wumin Quan1
  • Li Yang1
  • Chunquan Ou3,*,
  • Ling Sun1,*,

1Center of Reproductive Medicine, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, 510140 Guangzhou, Guangdong, China

2Clinical Laboratory, Zhujiang Hospital, Southern Medical University, 510280 Guangzhou, Guangdong, China

3State Key Laboratory of Organ Failure Research, Department of Biostatistics, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, 510515 Guangzhou, Guangdong, China

DOI: 10.31083/j.jomh1806124 Vol.18,Issue 6,June 2022 pp.1-6

Submitted: 12 August 2021 Accepted: 03 October 2021

Published: 30 June 2022

*Corresponding Author(s): Chunquan Ou E-mail:
*Corresponding Author(s): Ling Sun E-mail:

† These authors contributed equally.


Background: To evaluate the efficiency of bacterial clearance of different sperm preparation procedure. Methods: A total of 46 semen samples were collected in this study, each semen sample was divided into four equal parts (0.5 mL each). The first part was prepared by density-gradient centrifugation (D-group), the second part was prepared by swim-up (S-group), the third part was treated with density-gradient centrifugation combined with swim-up (D+S-group), and the fourth group was the original raw semen group (O-group) regarded as the control. After each semen preparation procedure, the O-group and suspensions were inoculated and incubated for bacterial identification and colony counting. Results: Initially only 8.7% (4/46) of samples were bacteria free. After processing, the bacterial clearance rates were 23.8% for D-group, 57.4% for S-group and 97.8% for D+S-group (p < 0.001). Multiple bacterial strains were observed in 37 samples with 117 different bacterial strains in all identified in the original semen. 44.4% of the staphylococci and 89.7% of streptococci were not eliminated in D-group. In S-group, the corresponding rates were 24.4% and 35.9%. In D+S-group there were no remaining strains of staphylococci and only 2.6% of streptococci remained. After the combined procedure, the number of bacterial colonies fell dramatically after processing. Conclusion: The combined D+S protocol appears to be substantially more efficient than either method alone in eliminating bacteria from semen samples.


Semen; Bacteria; Density-gradient centrifugation; Swim-up

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Zhiheng Chen,Lingxiao Jiang,Hui Wang1,Wumin Quan,Li Yang,Chunquan Ou,Ling Sun. Elimination of bacteria from semen using a combination of density gradient centrifugation and swim-up. Journal of Men's Health. 2022. 18(6);1-6.


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