Peptide fragment analysis of proinsulin (15-position cleavage) using serum/plasma
This test measures specific peptide fragments of proinsulin, a precursor protein to insulin, to help assess insulin production and function in your blood.
["Helps evaluate how well your body produces insulin from proinsulin."]
Key facts at a glance
- LOINC
- 25573-7
- Short code
- C peptide sp15 p chal SerPl-sCnc
- Synonyms
- C peptide sp15 p chal SerPl-sCnc
- Category
- coagulation
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 0.8
- Ref high
- 1.2
- Critical range
- — – 5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 85610
- SNOMED
- 396252006
- 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
Why This Test Is Done
Doctors may order this test if they suspect diabetes, prediabetes, or other conditions affecting insulin processing. It can also be used to monitor treatment for conditions like type 1 or type 2 diabetes.
What to Expect Before the Test
No special preparation is needed. You’ll provide a blood sample, usually drawn from a vein in your arm, similar to other blood tests. Your healthcare provider will explain the process and answer any questions.
What the Results Mean
The test measures the ratio of specific proinsulin fragments, which can indicate how efficiently your pancreas converts proinsulin into insulin. Abnormal results may suggest issues with insulin production or processing.
Common Conditions Monitored
This test is often used alongside other glucose-related tests to diagnose or manage diabetes, insulinoma (a rare tumor affecting insulin), or other metabolic disorders.
Reference range
INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A
Inform your healthcare provider if you are taking blood thinners. No special preparation required.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: This test provides insights into insulin synthesis and processing, which can be critical for diagnosing or managing diabetes-related conditions. Elevated or altered fragment levels may indicate impaired insulin production or dysfunction in the pancreas, helping tailor treatment plans.
Short name
Proinsulin fragment testing
Frequently asked questions
What does a high or low result mean?
How is this test different from a standard glucose test?
Is fasting required for this test?
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