Copper, Serum Free (Direct)
Ordering Recommendation
Quantitative Inductively Coupled Plasma-Mass Spectrometry
Tue, Thu, Sat
1-4 days  
New York DOH Approval Status
This test is New York DOH approved.
Submit With Order
Specimen Required
Patient Preparation
Diet, medication, and nutritional supplements may introduce interfering substances. Patients should be encouraged to discontinue nutritional supplements, vitamins, minerals, and non-essential over-the-counter medications (upon the advice of their physician).  
Royal blue (no additive).  
Specimen Preparation
Centrifuge. Transfer 2.5 mL serum to an ARUP Trace Element-Free Transport Tube. (Min: 1.5 mL) Do not allow serum to remain on cells.  
Storage/Transport Temperature
Unacceptable Conditions
Separator tubes. Specimens that are not separated from the red cells or clot.  
After separation from cells: Ambient: 8 hours; Refrigerated: 1 week; Frozen: 1 month  
Reference Interval
0.0-10.0 µg/dL  
Interpretive Data
Free copper (direct) is determined with serum ultrafiltrate. Results may be elevated in Wilson disease or other conditions of copper overload. Other tests used to diagnosis Wilson disease include serum ceruloplasmin, 24-hour urine copper, and hepatic copper. Slit lamp examination for Kayser-Fleischer rings and genetic testing may also be helpful.

Compliance Statement B: This test was developed and its performance characteristics determined by ARUP Laboratories. The U.S. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.
Elevated results from noncertified trace element-free tubes may be due to contamination.  Elevated concentrations of trace elements in serum should be confirmed with a second specimen collected in a trace element-free tube, such as royal blue sterile tube (no additive).
CPT Code(s)
Component Test Code*Component Chart NameLOINC
0020596Copper, Serum Free (Direct)5631-7
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
  • Copper Index
  • Cu
  • Cu, Plasma
  • CuFree
  • Free copper
  • Non-Ceruloplasmin Bound Copper
  • Unbound Copper