By Dhanush Kumar Kollu Babu, Marie Claire Aquilina, Shaun Rogers, and Peter J. I. Ellis
Why Sperm DNA Matters
When couples face fertility challenges, attention often turns to sperm count or motility — how many sperm there are, and how well they swim. But there’s another, less visible piece of the puzzle: the quality of the DNA inside each sperm cell.
Even when sperm look normal under a microscope, breaks or damage in their DNA can make it harder to achieve a healthy pregnancy. That’s why specialists increasingly use sperm DNA testing — an advanced way to look beyond the basics and understand the true health of sperm.
In many situations, men choose to preserve their sperm for the future, such as before cancer treatment, surgery, or advancing age. However, sperm cells are extremely delicate. Simply freezing semen without protection would damage or kill most of the sperm. To prevent this, fertility laboratories mix semen with special cryopreservation media — protective solutions that help sperm survive freezing and thawing while maintaining their structure and integrity.
While these preservatives are essential for sperm survival, there has been limited research on whether they might affect diagnostic tests — particularly those that measure DNA quality. To explore this, the University of Kent team carried out a new study using consented donor samples submitted for DNA fragmentation testing.
The Study
The research, which was presented at Fertility 2026, looked at whether these protective solutions — known as cryopreservation media — could change the outcome of sperm DNA tests.
The team compared samples frozen in three different ways: Neat Semen, Semen + Cryopreservation Media 1 and Semen + Cryopreservation Media 2.
After freezing and thawing, each sample was tested to measure the level of DNA damage.
What They Found
The results were remarkably consistent. No matter which freezing method was used, the DNA damage measurements came out the same.
These findings are reassuring for both fertility laboratories and sperm banks. They show that our standard DNA tests work just as well on frozen samples as on fresh ones. That means we can confidently assess the quality of stored sperm, whether it’s for donation or for men preserving their fertility before treatment.
In short, freezing sperm — and using protective additives — does not interfere with DNA testing results.
Why It Matters
This is reassuring news for patients and clinics alike. It means that frozen sperm can be tested for DNA quality just as accurately as fresh samples. That helps ensure the safety and effectiveness of sperm banking, fertility preservation, and assisted reproduction.
As highlighted by the Centre for Advanced Diagnostics Development and Application (CADDA) in their 2025 article “Sperm DNA Fragmentation Testing: Understanding the Clinical Need,” sperm DNA testing is becoming a key part of personalised fertility care. The Kent team’s findings strengthen that movement by confirming that DNA testing remains reliable even after cryopreservation.
The Takeaway
Whether sperm are used immediately, donated, or stored for years, these results show that modern DNA testing techniques remain accurate and trustworthy. For individuals planning ahead for their fertility — and for the clinics supporting them — that’s an important step forward in ensuring confidence and care in every stage of the reproductive journey.
Background reading:
1. Evenson, D. P. et al. (2002). Sperm chromatin structure assay and its clinical use. J Androl, 23(1).
2. Agarwal, A. et al. (2020). Clinical utility of sperm DNA fragmentation testing. Transl Androl Urol, 9(Suppl 2).
3. Sharma, R. et al. (2021). Impact of sperm DNA fragmentation on fertility outcomes. Reprod Biol Endocrinol, 19(1).
4. CADDA (2025). Sperm DNA Fragmentation Testing: Understanding the Clinical Need. www.cadda.org
5. Present study: Does Cryopreservation Media Influence AOFT Measurement of Sperm DNA Fragmentation? To be presented at Fertility 2026, UK.