C-Peptide

Cleveland HeartLab C, Metabolic, Test

NEW YORK DOH APPROVED: YES
CPT Code: 84681
Order Code: C136
ABN Requirement:  No
Synonyms: Connecting Peptide; Insulin C-Peptide; Proinsulin C-Peptide
Specimen: Serum
Volume: 0.5 mL
Minimum Volume: 0.2 mL
Container: Gel-barrier tube (SST, Tiger Top)

Collection:

  1. Collect and label sample according to standard protocols.
  2. Gently invert tube 5 times immediately after draw. DO NOT SHAKE.
  3. Allow blood to clot 30 minutes.
  4. Centrifuge for 10 minutes.

Patient Preparation: Patient should be fasting for 8-10 hours prior to being drawn.

Special Instructions: Samples should not be taken from patients receiving therapy with high biotin doses (>5 mg/day) until at least 8 hours following the last dose.

Transport: Store serum at 2°C to 8°C after collection and ship the same day per packaging instructions provided with the Cleveland HeartLab shipping box.

Stability:

Ambient (15-25°C): 4 hours
Refrigerated (2-8°C): 7 days
Frozen (-20°C): 30 days
Deep Frozen (-70°C): 30 days

Causes for Rejection: Samples which are heat-inactivated; samples stabilized with azide; specimens other than serum; improper labeling; samples not stored properly; samples older than stability limits

Methodology: Electrochemiluminescence Immunoassay (ECLIA)

Turn Around Time: 1 to 5 days

Reference Range:

Age ng/mL
All Ages 1.1-4.4

Intended Use: A C-peptide test may be used for individuals with newly-diagnosed diabetes to determine the degree of pancreatic beta-cell function, as well as for individuals with diabetes to determine whether to initiate insulin therapy. The test can also be used in individuals with suspected insulin resistance

Limitations: In rare cases, interference due to extremely high titers of antibodies to analyte-specific antibodies, streptavidin or ruthenium can occur.

The CPT codes provided 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 payer being billed.