Denny Sakkas
The Modern Laboratory · People
The Modern Laboratory
Denny Sakkas
He showed that a sperm can look perfect and still carry a damaged message.
Melbourne beginnings. Denny Sakkas studied at the University of Melbourne and earned his PhD at Monash University, at the Centre for Early Human Development in Clayton. His first papers, written with Alan Trounson from 1989, explored how early mouse embryos grow alongside cells from the reproductive tract.
Geneva and the sperm head. By the mid-1990s he was at the University Hospital of Geneva, working with colleagues at the University of Modena in Italy. Together they studied how tightly DNA is packed inside the sperm head, and how often it carries breaks. In 1996 his team examined eggs that had failed to fertilise after ICSI. When a man’s sperm DNA was more often poorly packed or damaged, those eggs far more often held a sperm head that had never unpacked.
Birmingham and Yale. He went on to direct IVF laboratories at Birmingham Women’s Hospital in England and then at Yale University School of Medicine. At Yale he led the laboratories of the Yale Fertility Center and a gamete biology research team. In 2004, with colleagues including David Gardner and William Schoolcraft, he showed that the more sperm in a sample carried broken DNA, the fewer embryos reached the blastocyst stage.
A wider view of the sperm. His reviews on where sperm DNA damage comes from helped the field see that a good sperm is more than a fast one. More recently he has worked on live imaging of human embryos to study their metabolism. He is Chief Scientific Officer at Boston IVF, and in 2025 he received the Distinguished Researcher Award of the American Society for Reproductive Medicine.
Also see: Alan Trounson, David Gardner, William Schoolcraft
About the sources
- Boston IVF. Dr. Denny Sakkas Receives 2025 ASRM Distinguished Researcher Award (bostonivf.com, October 2025): Chief Scientific Officer; directed IVF laboratories in Europe, the UK and the United States; live imaging of embryo metabolism.
- Beth Israel Deaconess Medical Center, PRECISE trial team. Dr. Denny Sakkas (research.bidmc.org): undergraduate training at the University of Melbourne; PhD at Monash University; Director of Assisted Reproductive Treatment Laboratories of the Yale Fertility Center; Gamete Biology Research Team; laboratory director of IVF units in Switzerland and England.
- Sakkas D, Alvarez JG. Sperm DNA fragmentation: mechanisms of origin, impact on reproductive outcome, and analysis. Fertility and Sterility 2010;93(4):1027–1036.
- Seli E, Gardner DK, Schoolcraft WB, Moffatt O, Sakkas D. Extent of nuclear DNA damage in ejaculated spermatozoa impacts on blastocyst development after in vitro fertilization. Fertility and Sterility 2004;82(2):378–383. PubMed 15302287 (Yale University School of Medicine).
- Sakkas D, Mariethoz E, Manicardi G, Bizzaro D, Bianchi PG, Bianchi U. Origin of DNA damage in ejaculated human spermatozoa. Reviews of Reproduction 1999;4(1):31–37 (Assisted Conception Unit, Birmingham Women’s Hospital).
- Sakkas D, Urner F, Bianchi PG, Bizzaro D, Wagner I, Jaquenoud N, Manicardi G, Campana A. Sperm chromatin anomalies can influence decondensation after intracytoplasmic sperm injection. Human Reproduction 1996;11(4):837–843. PubMed 8671337 (University Hospital of Geneva).
- Manicardi GC, Bianchi PG, Pantano S, Azzoni P, Bizzaro D, Bianchi U, Sakkas D. Presence of endogenous nicks in DNA of ejaculated human spermatozoa and its relationship to chromomycin A3 accessibility. Biology of Reproduction 1995;52(4):864–867 (Department of Animal Biology, University of Modena).
- Sakkas D, Trounson AO. Co-culture of mouse embryos with oviduct and uterine cells prepared from mice at different days of pseudopregnancy. Journal of Reproduction and Fertility 1990;90(1):109–118. PubMed 2231532.
- Sakkas D, Trounson AO, Kola I. In vivo cleavage rates and viability obtained for early cleavage mouse embryos in co-culture with oviduct cells. Reproduction, Fertility and Development 1989;1(2):127–136. PubMed 2798942 (Centre for Early Human Development, Monash Medical Centre, Clayton).
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Compiled with AI-assisted research and checked against the original sources. Not yet peer-reviewed. Corrections are warmly welcomed.
