Creatine Biosynthesis Disorders Panel, Urine

Test Codes

EPIC: LAB1231996, Beaker: BIOSYNTH, Quest: 94600

Department

Send Outs

Instructions

NOTE: Includes Guanidinoacetate, Creatine, Creatinine, Creatine/Creatinine.

Specimen Collection Criteria

Collect (preferred specimen): Random 1.0 mL urine specimen in a sterile screw-capped container (preferred) or other sterile collection cup. (Minimum: 0.5 mL)

Send specimen for processing immediately after collection.

Physician Office/Draw Specimen Preparation

Freeze (-20°C/-4°F or below) immediately.

Preparation for Courier Transport

Transport: 1.0 mL random urine, frozen (-20°C/-4°F or below). (Minimum: 0.15 mL)

Rejection Criteria

• Specimen not frozen immediately after collection.
• Specimens not collected and processed as indicated.

In-Lab Processing

Freeze (-20°C/-4°F or below) immediately.

Transport: 1.0 mL random urine, frozen (-20°C/-4°F or below). (Minimum: 0.15 mL)

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): Unacceptable
Refrigerated (2-8°C or 36-46°F): Unacceptable
Frozen (-20°C/-4°F or below): 28 days

Specimen Storage in Department Prior to Disposal:

Specimen retention time is determined by the policy of the reference laboratory. Contact the Send Outs Laboratory with any questions.

Laboratory

Sent to Quest Diagnostics, Wood Dale, IL.

Performed

Tuesday.
Results are available in 4-7 days.

Reference Range

By report.

Test Methodology

Liquid Chromatography / Tandem Mass Spectrometry (LC/MS/MS).

CPT Codes

82540, 82542, 82570

Contacts

Last Updated

11/19/2025