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Test Code CK Creatine Kinase (CK), Serum

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Serum


Necessary Information


Patient's age and sex are required.



Specimen Required


Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions:

1. Serum gel tubes should be centrifuged within 2 hours of collection.

2. Red-top tubes should be centrifuged, and the serum aliquoted into a plastic vial within 2 hours of collection.


Specimen Minimum Volume

0.25 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Refrigerated (preferred) 7 days
  Frozen  28 days
  Ambient  48 hours

Reference Values

Males

≤3 months: not established

>3 months: 39-308 U/L

Females

≤3 months: not established

>3 months: 26-192 U/L

Reference values have not been established for patients that are less than 3 months of age.

Note: Strenuous exercise or intramuscular injections may cause transient elevation of creatine kinase (CK).

Day(s) Performed

Monday through Sunday

CPT Code Information

82550

Clinical Information

Creatine kinase (CK) is an enzyme that catalyzes the reversible phosphorylation of creatine (Cr) by adenosine triphosphate (ATP). Physiologically, when muscle contracts, ATP is converted to adenosine diphosphate (ADP), and CK catalyzes the rephosphorylation of ADP to ATP using creatine phosphate as the phosphorylation reservoir. The CK enzyme is a dimer composed of subunits derived from either muscle (M) or brain (B). Three isoenzymes have been identified: striated muscle (MM), heart tissue (MB), and brain (BB). Normal serum CK is predominantly the CK-MM isoenzyme.

 

CK activity is greatest in striated muscle (MM isoenzyme ), heart tissue (MB isoenzyme ), and brain (BB isoenzyme ). Serum CK concentrations are reflective of muscle mass causing males to have higher concentrations than females. CK may be measured to evaluate myopathy and to monitor patients with rhabdomyolysis for acute kidney injury.

Report Available

Same day/1 to 2 days

Reject Due To

Gross hemolysis Reject

Method Name

Photometric, Creatine Phosphate + ADP