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Test Code LAB62 Creatine Kinase (CK) Total, Blood

Performing Laboratory

St. Louis Children's Hospital - Chemistry

Specimen Requirements

Patient Preparation: None

Container/Tube  
Preferred: Mint green-top Lithium heparin (MNTGRN LiHep) tube
Acceptable: Green samplette/microtainer, plain red-top tube, Gold SST gel tube, or Lavender-top (EDTA) tube
Collection Volume: 1.0 mL (minimum 0.6 mL)

Submission Container/Tube: If specimen is coming from outside facility and collected in a microtainer, plain red-top tube, or Lavender-top (EDTA) tube aliquot processed sample into a plastic vial for transport (labeling with specimen type).
Special Instructions: Avoid prolonged venous stasis when collecting the specimen. Send to lab promptly.

Sample Rejection

Mislabeled or unlabeled specimens

Logistics

Test Availability: Monday-Sunday
Cut-off time: None; performed as received
Turnaround Time: Same day; 2 hours from receipt in performing lab

Reference Values

Reference Intervals:

Males:               
  < 18 years: ≤ 300 Units/L
  ≥18 years: 40-300 Units/L                                                                        
Females:
  <18  years: ≤ 300 Units/L
  >or=18 years: 30-200 Units/L

Critical Values: >5000 Units/L

Critical test results will be automatically called back initially and every 168 hours thereafter.

Methodology

UV Enzymatic (NADH)

Limitations

  • In vary rare cases gammopathy, in particular IgM (Waldenstrom's macroglobulinemia), may cause unreliable results.
  • Cyanokit (Hydroxocobalamin) may cause interference with results

For diagnostics purposes, the results should always be assessed in conjunction with the patient's medical history, clinical examination, and other findings.

Additional Information

FOR SLCH CORE LABORATORY USE ONLY

Lab Processing Instructions: Centrifuge specimen to separate. If specimen is collected in a microtainer, plain red-top tube, or Lavender (EDTA) tube, aliquot sample into a Roche false bottom tube for testing (labeling with specimen type)
Processed Volume: 0.3 mL plasma/serum
Analyte Stability:

Specimen Type Temperature Time
Whole Blood (unprocessed)  Ambient 8 hours
Plasma/Serum (processed) Refrigerated (preferred) 5 days
  Ambient  8 hours
  Frozen  1 month

Test Classification and CPT Code

82550

LOINC

2157-6

Last Reviewed

06/2025