Test Name

C-Peptide

Test Code

645

Unit

ng/mL

Station

Immulite

Synonym Name/Abbreviation

Connecting Peptide, Insulin
C-Peptide

CPT Code

84681

Performing Facility

American Medical Labs, Herzliya
Pituah

Analyzer

Siemens Immulite 2000

Test Method

Immunochemiluminometric assay
(ICMA)

AML Preferred Tube

5 mL SST gel

Storage Instructions

Frozen -20 ^oC.

Separate serum from cells within 45 minutes.

Stability:

assay within
2- 3 hours, up to 1 week at
-20 ^oC.

Min. Volume

1 mL

Comments

Freeze immediately after
centrifugation.

Turn-Around-Time

5 working days

Intended Use

 C-peptide is
principally used as an aid in diagnosis and treatment of patients with
abnormal insulin secretion and for evaluation of hypoglycemic disorders (
insulinoma, exogenous insulin or oral hypoglycemic drugs, pituitary or
adrenal insufficiency, severe hepatic disease).

Limitations

C-peptide levels are increased with renal failure. Instances
of insulinoma have been described in which proinsulin was increased but
insulin and C-peptide were not. Values obtained with different assay
methods should not be used interchangeably in serial testing. It is
recommended that only one assay method be used consistently to monitor
each patient’s course of therapy.

Measuring range: 0.1 to 20
ng/mL.

Patient Preparation

Patient should fast for 14-16 hours for basal
values.

Reasons for Rejection

Patient not fasting; specimen not
frozen

Adult Reference Ranges

1.1 to 3.1
ng/mL