Test Details
Methodology
Electrochemiluminescence immunoassay (ECLIA)
Result Turnaround Time
1 - 2 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Use
Reflects the patient's beta cell function. It, therefore, is a marker for endogenous insulin production with or without exogenous insulin injection. C-peptide is not affected by the presence or absence of insulin antibodies.
Special Instructions
This test may exhibit interference when sample is collected from a person who is consuming a supplement with a high dose of biotin (also termed as vitamin B7 or B8, vitamin H, or coenzyme R). It is recommended to ask all patients who may be indicated for this test about biotin supplementation. Patients should be cautioned to stop biotin consumption at least 72 hours prior to the collection of a sample.
Specimen Requirements
Specimen
Serum
Volume
1 mL
Minimum Volume
0.5 mL (Note: This volume does not allow for repeat testing.)
Container
Red-top tube or gel-barrier tube
Collection Instructions
If a red-top tube is used, transfer separated serum to a plastic transport tube. Avoid hemolysis.
Stability Requirements
Temperature | Period |
|---|---|
Room temperature | 1 day |
Refrigerated | 14 days |
Frozen | 14 days |
Freeze/thaw cycles | Stable x3 |
Storage Instructions
Refrigerate
Causes for Rejection
Citrate plasma specimen; hemolyzed specimen
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 213660 | Insulin and C-Peptide, Serum | 004333 | Insulin | uIU/mL | 20448-7 | |
| 213660 | Insulin and C-Peptide, Serum | 010109 | C-Peptide, Serum | ng/mL | 1986-9 | |
| Order Code | 213660 | |||||
| Order Code Name | Insulin and C-Peptide, Serum | |||||
| Order Loinc | ||||||
| Result Code | 004333 | |||||
| Result Code Name | Insulin | |||||
| UofM | uIU/mL | |||||
| Result LOINC | 20448-7 | |||||
| Order Code | 213660 | |||||
| Order Code Name | Insulin and C-Peptide, Serum | |||||
| Order Loinc | ||||||
| Result Code | 010109 | |||||
| Result Code Name | C-Peptide, Serum | |||||
| UofM | ng/mL | |||||
| Result LOINC | 1986-9 |