Changes in DNA fragmentation during sperm preparation for intracytoplasmic sperm injection over time

We assessed sperm DNA fragmentation (TUNEL) at different time periods before ICSI, and found DNA fragmentation significantly decreased after gradient and samples with TUNEL >20% were more susceptible to a significant increase over time.

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Natalia Rougier, M.D., Heydy Uriondo, M.Sc., Sergio Papier, M.D., Miguel Angel Checa, M.D., Ph.D., Carlos Sueldo, M.D., Cristian Alvarez Sedó, M.Sc.

Volume 100, Issue 1, Pages 69-74, July 2013



To compare the DNA fragmentation of semen samples established by terminal deoxynucleotide transferase–mediated dUTP nick-end labeling (TUNEL) after incubation in polyvinylpyrrolidone (PVP) and hyaluronic acid (HA) for different time periods.


Comparative prospective study.


Center for reproductive medicine.


Twenty-seven semen samples from infertile patients.




Semen analysis and DNA fragmentation assays (TUNEL) were performed. Two groups were established: A) normal TUNEL (<20%); and B) Abnormal TUNEL (≥20%). TUNEL was performed in neat (T0), postgradient (TG), 1-hour postgradient (TG1), and 2-hour postgradient (TG2) samples and in TG2 samples after 0.5, 1.0, and 1.5 hours of incubation in PVP or HA.


TUNEL levels were significantly reduced after gradient separation compared with neat values. In group A, TUNEL levels were significantly higher in the TG2 + 1.5 hours in PVP and HA samples but did not reach abnormal levels. In group B, TUNEL levels were significantly higher in the TG2 + 1 hour in PVP and HA samples.


Sperm DNA fragmentation significantly decreased after centrifugation gradient, regardless of the initial levels of the sample. Samples with TUNEL ≥20% were more susceptible to a significant increase in DNA fragmentation over time, with similar increases being observed over time for samples that were incubated in HA or PVP. These data may be relevant for sperm preparation for intracytoplasmic sperm injection.

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Fertility and Sterility

Editorial Office, American Society for Reproductive Medicine

Fertility and Sterility® is an international journal for obstetricians, gynecologists, reproductive endocrinologists, urologists, basic scientists and others who treat and investigate problems of infertility and human reproductive disorders. The journal publishes juried original scientific articles in clinical and laboratory research relevant to reproductive endocrinology, urology, andrology, physiology, immunology, genetics, contraception, and menopause. Fertility and Sterility® encourages and supports meaningful basic and clinical research, and facilitates and promotes excellence in professional education, in the field of reproductive medicine.