Fibrinogen Antigen, Nephelometry Test
This test measures fibrinogen antigen in a plasma sample using nephelometry. Fibrinogen is a protein involved in blood clotting that also rises with inflammation, and results are read alongside a person's symptoms and history.
About this test
Fibrinogen is a protein central to blood clotting, and this test measures its level in plasma using nephelometry, a method that assesses protein concentration by how a sample scatters light. The sample is 1 mL of plasma, collected in a citrate tube.
Low fibrinogen levels are associated with bleeding, most often linked to liver disease or disseminated intravascular coagulation (DIC), while elevated levels are associated with inflammation and an increased risk of atherosclerosis. Because fibrinogen can move in either direction depending on what is happening in the body, a clinician reads the result together with a person's history and other findings.
Who might consider this test?
- Often being evaluated for a bleeding tendency
- As part of a broader look at cardiovascular risk
- Since fibrinogen is linked to both clotting and inflammation
Test details
| Quest code | 37801 |
|---|---|
| Methodology | Nephelometry |
| Sample type | 1 mL plasma |
| Patient preparation | Fast overnight before your blood draw. |
| Collection | Quest patient service center |
Reference range
180-350 mg/dL
Reference ranges are general guidance. The range printed on your own laboratory report is the one that applies to your result.
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Additional details
What this test looks at
The test reports a single value: the concentration of fibrinogen antigen in plasma. Fibrinogen levels can move in either direction — low levels toward bleeding tendencies, most often tied to liver disease or DIC, and high levels toward inflammation and elevated cardiovascular risk — which is why a clinician always reads the number alongside symptoms and history rather than as a stand-alone answer.
Order online and a physician order is included — no doctor's visit and no insurance needed. Your sample is collected at a Quest Diagnostics patient service center.
Laboratory results should always be interpreted by a licensed clinician who knows your health history. This page is information about a test, not medical advice.
Frequently asked questions
What does this test measure?
It measures the concentration of fibrinogen antigen in a plasma sample, using a nephelometry method.
How is the sample collected?
The test uses a plasma sample, collected in a citrate tube, from a routine blood draw at a Quest Diagnostics patient service center.
Do I need to prepare for this test?
Fast overnight before your blood draw. This is the preparation Quest publishes for this test; if your clinician gives you different instructions, follow theirs.
What can affect fibrinogen levels?
Low levels are associated with bleeding, often linked to liver disease or disseminated intravascular coagulation (DIC), while high levels are associated with inflammation and increased cardiovascular risk. A clinician interprets the result together with symptoms and history.
Can I get the Fibrinogen test without a doctor's visit or insurance?
Yes. The $115 cash price includes an independent physician's order, so no referral is needed, and insurance is never involved.