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Cell-free DNA (cfDNA) quantitative analysis using a specific genetic probe (e.g., for tumor DNA detection)

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

This test measures tiny pieces of DNA found naturally in your bloodstream, often used to detect genetic material from tumors or other conditions.

Quick summary

["This test helps identify abnormal DNA that may signal cancer or other genetic changes."]

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

Key facts at a glance

LOINC
4999-9
Short code
CMV DNA Ur Ql NAA+probe
Synonyms
CMV DNA Ur Ql NAA+probe
Category
chemistry
Sample
urine
Container
Sterile urine container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
probe-amp-tar
Specimen volume
10 mL
Stability
Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

What Is This Test Measuring?

Your blood contains small fragments of DNA called cell-free DNA (cfDNA). This test focuses on detecting specific sequences of DNA, often linked to cancer or other genetic conditions, using a specialized genetic probe. The probe binds to particular DNA sequences that may be present in higher amounts in certain diseases.

Why Might You Need This Test?

This test may be used in certain situations, such as monitoring for cancer recurrence, guiding treatment decisions, or assessing genetic risks in specific clinical scenarios. It is particularly relevant in oncology for detecting tumor DNA that may not be visible on standard imaging.

How Is the Sample Collected?

A blood sample is drawn from a vein, typically in your arm. The blood is processed to separate the cell-free DNA from the rest of the blood components. The genetic probe is then used to analyze the DNA fragments for specific sequences.

What Does the Result Mean?

Results are qualitative (present or absent) or quantitative (relative concentration) for the specific DNA sequences tested. A positive result may indicate the presence of abnormal DNA, such as from a tumor, but further evaluation by a healthcare provider is needed to interpret the clinical significance.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Frequently asked questions

What does a positive result mean?
A positive result suggests the presence of the specific DNA sequences tested, which may be linked to cancer or other genetic conditions. This finding should be discussed with your healthcare provider to determine the next steps, as additional tests or evaluations may be needed to confirm or explore further.
How often is this test repeated?
The frequency of retesting depends on your medical condition and treatment plan. Your healthcare provider will determine how often this test should be repeated, often as part of ongoing monitoring for conditions such as cancer.
Can this test detect all types of cancer?
This test is designed to detect specific genetic sequences associated with certain cancers or conditions. It may not detect all types of cancer, and results should be interpreted in the context of your overall medical history and other diagnostic tests.
  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