The Science Behind SpermComet®

Exact tests, powered by SpermComet® are the sperm DNA tests of choice amongst consultants in 80% of the UK’s leading fertility clinics

SpermComet® is our proprietary molecular technology that powers the Exact range of market-leading sperm DNA tests: Exact Fertility™, Exact IVF™ and Exact ICSI™

SpermComet® technology looks inside your sperm to check the quality of its DNA. Sperm DNA can be damaged during sperm production and while it is being stored in your body. This damage is known as DNA fragmentation. High levels of sperm DNA fragmentation are associated with delayed natural conception and repeated miscarriage. Sperm DNA fragmentation also reduces the success of fertility treatments like IVF.

The Science Behind SpermComet®

Sperm DNA Fragmentation

What causes damage to sperm DNA?

Damage to sperm DNA is mostly caused by oxidative stress via free radicals. Free radicals attack the DNA resulting in single or double-strand breaks in the DNA molecule itself and producing single or double-stranded DNA fragments (Figure 1). Sperm do not have the cellular machinery to repair DNA damage so even men who are dads have some damage in their sperm. The amount of damage caused can vary from one sperm to another. But once the damage reaches a certain level it can cause fertility problems.

The SpermComet® test

How does SpermComet work?

SpermComet® technology is based on a technique known as single cell gel electrophoresis. It measures the amount of single- and double-strand DNA fragments present in individual sperm, generating a picture of the extent of DNA fragmentation throughout a sample (Figure 2). This detailed examination of a sample is what makes our Exact range the most accurate male fertility tests available.

Learn about the test

Sign up for our mailing list

Enter your email address to receive the latest updates and published papers related to Exact tests.

For Healthcare Professionals


  • Unit 18A Block K
  • Weavers Court Business Park
  • Linfield Road
  • Belfast BT12 5GH

© 2019 Examen Ltd. Website Design by Bag of Bees