Insulin, Free-Binding, Serum/Plasma — Qualitative
A qualitative serum or plasma test that evaluates whether free insulin is detectable in the blood.
["This test reports whether free insulin is detectable and must be interpreted with glucose and other insulin results."]
Key facts at a glance
- LOINC
- 44462-0
- Short code
- Insulin Free+Bnd SerPl Ql
- Synonyms
- Insulin Free+Bnd SerPl Ql
- Category
- hormone
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 2.6
- Ref high
- 24.9
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 83525
- SNOMED
- 413618004
- 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 is this test?
This is a qualitative laboratory test for free insulin in a serum or plasma blood sample. It generally reports whether free insulin was detected rather than providing a numeric concentration.
Why might I need this test?
A clinician may order this test when insulin results do not fit the clinical situation or when evaluating unusual blood glucose patterns. It may be considered with tests such as glucose, total insulin, and C-peptide to assess insulin production or the possible use of injected insulin.
How is the test performed?
Blood is collected and separated into serum or plasma. The laboratory uses a specialized assay to determine whether free insulin is present, with the result usually reported as detected or not detected.
How do I prepare for the test?
Follow the testing instructions provided by your clinician. The test may need to be fasting or timed closely to a meal or insulin dose, and you should not change insulin therapy unless your healthcare professional tells you to.
Reference range
Fasting: 2.6-24.9 μIU/mLN/A
No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
A detected result means that free insulin was measurable in the sample. A not-detected result means it was below the laboratory assay's detection threshold. This result alone does not diagnose diabetes, insulin resistance, or an insulin-producing condition and should be interpreted with glucose levels, medication use, collection timing, and other insulin tests.
Short name
Free insulin binding
Frequently asked questions
What does a qualitative result mean?
Why is the specimen listed as serum or plasma?
Can this test diagnose diabetes or insulin resistance?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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