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Insulin, C-peptide

Item Value
Test Update Information Method changed from Siemens Centaur XP platform to Abbott Architect i2000 platform on 9/14/2017. Please note that the reference ranges have changed.

The Architect C-Peptide Calibrators are established against a set of Internal Reference Calibrators, which are traceable to the WHO International Reference Reagent for C-Peptide of human insulin for immunoassay, code 84/510, established 1986, from the National Institute for Biological Standards and Control (NIBSC).
Approval req'd? No
Available Stat? No
Test code CPEP
Performed by China Basin Chemistry
In House Availability Test available once a week on day shift (Wednesdays)
Method Chemiluminescent Microparticle Immunoassay (Abbott Architect i2000)
Patient Preparation An overnight fast is required prior to specimen collection or reference ranges will not apply.
Collection Instructions Deliver to lab immediately. Call physician if patient is not fasting to see if the specimen is acceptable.
Container type Gold top or Red top
Amount to Collect 2 mL blood
Sample type Serum
Preferred volume 1 mL serum
Min. Volume 0.150 mL serum
Processing notes Centrifuge promptly. Freeze serum at -20C.
Units ng/mL
Normal range
Fasting 0.8-3.5 ng/mL


Reference range was adopted from ARUP and verified in-house using sample collected by 25 fasting lab donors.

Note: if patient was not fasting the normal ranges may not apply.

Synonyms Insulin, C-Peptide
Stability Room temperature: Stable for 24 hours
Refrigerated (2-8°C): Stable for 48 hours
Frozen at -20°C or colder: Stable for 3 months

Avoid more than 3 freeze/thaw cycles.
Turn around times Test performed Wednesdays.
Additional information The specificity of the ARCHITECT C-peptide assay is designed to have ≤ 0.01% cross-reactivity when tested with compounds listed in the table below. For proinsulin the assay is designed to have ≤ 40% cross-reactivity.

Substance Concentration Cross-reactivity (%)
Human Insulin 8660 ng/mL 0
Glucagon 10000 ng/mL 0
Human proinsulin 100 ng/mL 12.8
Secretin 15000 ng/mL 0
Somatomedin-C (IFG-1) 1000 ng/mL 0

CPT coding 84681
LOINC code 1986-9
Last Updated 9/14/2017 1:14:01 PM
Entry Number 148
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