C Peptide Mnemonic C PEPTIDE Synonym C Pep - CPS - C-PEPTIDE Specimen Collection Requirements Patient Preparation Fasting specimen is preferred. Collect Serum, one 5.0 mL gold (SST) or 7.0 mL red top tube Supply Item Number - 101235 or 101192 Handling Allow serum tubes to clot completely at room temperature (minimum - SST: 30 minutes, red top tubes: 60 minutes). Centrifuge and separate serum from cells ASAP. Preferred Volume 1.0 mL Serum Minimum Volume 0.3 mL Serum (0.8 mL minimum whole blood draw) Transport Frozen (≤ -20°C) Rejection Criteria Grossly hemolyzed or plasma specimens Specimens that have been thawed more than once Stability AFTER SEPARATION FROM CELLS: Room Temperature (18-26°C): 8 hours; Refrigerated (2-8°C): 24 hours; Frozen (≤ -20°C): 1 month. Do not thaw specimens more than once. Testing Information Performed Mon, Wed, Fri Reported 24-72 hours Method Chemiluminescent Assay Reference Values Reference Values All: 0.8 - 3.8 ng/mL Reference range applies to fasting specimens. CPT Codes 84681 Last Updated: Thursday, February 11, 2021 07:27:44 PM Client Services: 503-413-1234