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Sperm Chromatin Structure Assessment (SCSA) by Flow Cytometry

Published: August 9, 2026Updated: August 16, 2026

This test evaluates the integrity of sperm DNA packaging, which is critical for successful fertilization. Abnormalities may suggest issues with sperm quality or fertility.

Quick summary

["Assessing sperm DNA protection helps identify potential fertility challenges."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
66494-6
Short code
Sperm acrosome defects NFr Smn
Synonyms
Sperm acrosome defects NFr Smn
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What This Test Measures

The SCSA test uses flow cytometry to measure the degree of sperm DNA compaction. Healthy sperm DNA is tightly packed, while loosely packed DNA (often due to oxidative stress or other damage) can affect fertility. This test specifically looks at the **DNA fragmentation index (DFI)**, which reflects how much of the sperm DNA is compromised.

Why It Matters for Fertility

Properly packaged sperm DNA is essential for proper chromosome function during fertilization. Loosely packed DNA can lead to failed implantation, recurrent miscarriages, or developmental issues in the embryo. This test helps doctors determine whether sperm DNA integrity is a contributing factor to infertility.

How the Test Is Performed

A semen sample is collected and analyzed using flow cytometry. The test measures the **red fluorescence** emitted when sperm DNA is exposed to acridine orange dye, which binds to single-stranded DNA. Higher fluorescence indicates more DNA damage.

Common Reasons for Testing

Doctors may recommend this test if you or your partner experience unexplained infertility, recurrent pregnancy loss, or if previous fertility treatments (like IVF) have not been successful. It’s also used in cases of male infertility where other tests (like sperm count or motility) are normal.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

SCSA Test

Frequently asked questions

How often will I need this test?
This test is typically ordered as part of a fertility evaluation. Your doctor may recommend it once or multiple times, depending on your medical history and treatment plan. Results may guide decisions about assisted reproductive technologies (ART) or further diagnostic steps.
What do my results mean?
Results are usually reported as a **DNA fragmentation index (DFI)**, which compares the percentage of sperm with damaged DNA to those with intact DNA. A higher DFI suggests increased risk of fertility issues. While exact reference ranges vary by lab, a DFI above 30% is often considered abnormal and may warrant further investigation or treatment.
Can lifestyle changes improve my sperm DNA quality?
Yes! Improving sperm DNA integrity often involves reducing oxidative stress. This can be achieved through lifestyle changes like quitting smoking, limiting alcohol, managing stress, maintaining a healthy weight, and consuming a balanced diet rich in antioxidants (e.g., fruits, vegetables, omega-3 fatty acids). Some studies also suggest supplements like vitamin C, E, and coenzyme Q10 may help.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy