Calcium, Ionized, Serum
Use to assess calcium status.
Ion-Selective Electrode/pH Electrode
Within 24 hours
New York DOH Approval Status
Serum separator tube.
Do not open the tube or split the specimen. Do not freeze separator tube. Do not expose specimen to air at any time during collection or transport process. Centrifuge with stopper in place within one hour of collection. Transport 5 mL serum in original serum separator tube. (Min: 0.5 mL)
Refrigerated. Ship upright in original serum separator collection tube and transport in the ARUP shipping rack. Do not ship on dry ice.
Plasma and samples exposed to air in aliquot tubes. Frozen specimens.
Ambient: 24 hours; Refrigerated: 1 week; Frozen: Unacceptable
Ionized calcium (ISE):
Ionized calcium (calculation at pH 7.4):
Differences between the ionized calcium result and the ionized calcium normalized to pH 7.4 are due to the sample having a pH significantly different from pH 7.4. Specimen pH may be artificially decreased due to delayed processing and may be increased when the specimen is exposed to air. Due to these factors, it is recommended that the ionized calcium normalized to pH 7.4 be interpreted with caution and only used when the clinician has knowledge of the patient's acid/base status. Accurate determination of in vivo pH is best determined by arterial blood gas testing.
|Component Test Code*||Component Chart Name||LOINC|
|0020136||Calcium, Ionized Serum||12180-6|
|0020138||Calcium Ionized pH 7.4||19072-8|
- CA Ionized, Serum
- Free Calcium
- Ionized Calcium