Calcium, Ionized

Supply #T01 - Red/Gray SST 8.5mL

Test Code: 306

Includes: Ionized Calcium

Methodology: Ion Specific Electrode

Clinical Significance: The ionized calcium is determined by an ion selective electrode methodology. The result that is generated is pH adjusted. The result is empirically based on a measured pH of ionized calcium concentration normalized to a pH of 7.40. This calculation compensates for in-vitro changes in pH due to loss of CO2 through specimen handling. Ionized calcium represents the true “bioavailable” calcium in the circulation. In situations where the total calcium is normal but does not fir the clinical picture (e.g. hyperparathyroidism) a determination of the ionized calcium will, many times, show an elevation in the “bioavailable” calcium component. This may be due to alterations in protein concentrations, especially albumin, which binds most of the calcium in the circulation.

Alternative Name(s): Free Calcium; Ionized CA; CA++; CA, Ionized; Calcium; Calcium Free; Free CA; Ionized Calcium

Collection Guide: 

Supply: T01 - Red/Gray SST 8.5mL

Preferred Specimen: Serum

Preferred Volume: 2mL

Transport Container: Serum Separator Tube (SST) - Spun and UNOPENED

Transport Temperature: Room Temperature

Specimen Stability: Room Temperature: 1 Week

SPECIAL INSTRUCTIONS: Let clot and spin immediately with the cap on. DO NOT OPEN TUBE. Ship the UNOPENED gel barrier tube at room temperature. If submitting with any other assay, PLEASE SUBMIT A SEPARATE TUBE FOR THIS TEST.

Rejection Criteria:

  • Received frozen
  • Received opened or poured off

For additional supply or collection device information, please contact DLO's Customer Service at (800) 891-2917, option 2.