C-Peptide

Message

For Specimen Integrity during Extreme Weather see the “Lockbox Usage in Extreme Weather” document at the top of this page.

Test Code

CPEP

Alias/See Also

372

CPT Codes
84681

Preferred Specimen

serum

Minimum Volume

1 mL

Other Acceptable Specimens

plasma from Lithium Heparin (Light Green Top)tube

Instructions

Barrier tubes (serum separator tubes or plasma separator tubes) are preferred. If non-barrier tubes are utilized, the serum/plasma must be removed immediately after centrifuging and placed in a screw-cap transfer tube.

Collection notes: Avoid hemolysis. Invert tubes at least 8 times. Allow to clot in an upright position for 30 minutes. Within 2 hours, centrifuge tubes 10 minutes. Keep tightly stoppered.

Do NOT re-centrifuge tubes. Do NOT freeze the primary collection tube.

Transport Container

Original tube preferred, may be sent in a screw-top transfer tube.

Transport Temperature

Refrigerated or Frozen

Specimen Stability

Room temperature = 4 hours
Refrigerated = 24 hours
Frozen = 30 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Hemolysis, Lipemia, incorrect specimen type, insufficient sample volume, improper storage conditions, exceeds specimen stability guidelines, contaminated sample.

Methodology
immunoassay

Setup Schedule

Daily
RI

Report Available

daily

Clinical Significance

C-Peptide is useful in the evaluation of pancreatic beta cell function and for determining the source of insulin in patients with hyperinsulinemic hypoglycemia.

Performing Laboratory
Compunet Clinical Laboratories, LLC
2308 Sandridge Drive
Moraine, OH 45439

Last Updated: November 22, 2021

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.