Sperm DNA Fragmentation (SDF) Tests for Advanced Diagnosis

Conventional semen analysis has limited diagnostic value for male infertility and poor predictive value for assisted reproductive technology (ART) success. Exact and Extend go beyond basic metrics to uncover the root cause of male infertility and failed fertility treatments.

Our ISO-accredited Sperm DNA Fragmentation (SDF) tests are powered by our SpermComet® assay, which applies a highly sensitive technique called single-cell gel electrophoresis. This method gently unwinds the tightly packed DNA within each sperm cell so that any DNA fragmentation present can be directly measured. 

The Comprehensive Diagnostic

Exact® – when TTC is proving difficult

Key Clinical Applications

The Recurrent Miscarriage & IVF Prediction Specialist

Extend® – when miscarriage or ART failure is present

Key Clinical Applications

Specialised Exact® and Extend® SDF Tests for special sample types

  • ExactFocus / ExtendFocus: designed for severe oligozoospermia samples (less than 5M/ml concentration) and suitable for sample concentrations of 0.01M/ml to 5M/ml
  • ExactPrep / ExtendPrep: for all prepared ejaculate sperm samples, including those processed using methods such as density gradient, centrifuge, Zymot and microfluidic plates
  • ExactSSR: a specialised variant for samples obtained via surgical sperm retrieval methods such as TESA, PESA, MESA, TESE, and micro-TESE

Detailed Test Specifications and Summaries

Exact Tests
(Total SDF damage)
ExactExactFocusExactPrepExactSSR
MeasuresTotal SDF damage (single and double strand breaks)
Used forSperm concentrations above 5M/mlSperm concentrations below 5M/mlPrepared ejaculate samples (e.g. prepared for ICSI, Zymot, DG, nMx, etc.)Surgically retrieved sperm samples (using TESA, PESA, MESA, TESE, and micro-TESE)
Applications and Measurement Scope for Exact® Sperm DNA Fragmentation (SDF) Tests: This table details the specific variants of the Exact® tests (Exact, ExactFocus, ExactPrep, ExactSSR) and their intended use based on sperm concentration and sample preparation type, all of which measure Total SDF damage (single and double strand breaks).
Extend Tests
(Double-Strand SDF damage)
ExtendExtendFocusExtendPrep
MeasuresDouble-strand DNA breaks (dsDB) damage
Used forSperm concentrations above 5M/mlSperm concentrations below 5M/mlPrepared ejaculate samples (e.g. prepared for ICSI, Zymot, DG, nMx, etc.)
Applications and Measurement Scope for Extend® Sperm DNA Fragmentation (SDF) Tests: This table outlines the specific variants of the Extend® tests (Extend, ExtendFocus, ExtendPrep) and their intended use based on sperm concentration and sample preparation type, all of which are designed to measure Double-strand DNA breaks (dsDB) damage.
Test Bundles
Exact + ExtendExactFocus + ExtendFocusExactPrep + ExtendPrep
MeasuresTotal SDF and dsSDF damage
Used forSperm concentrations above 5M/mlSperm concentrations below 5M/ml (severe oligozoospermia)Prepared ejaculate samples (e.g. prepared for ICSI, Zymot, DG, nMx, etc.)
Intended Use for Combined Exact® + Extend® Test Bundles: This table presents the combined test bundles, detailing their use for comprehensive analysis of Total SDF and dsSDF damage across various sperm concentrations and sample types, including cases of severe oligozoospermia.
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