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HelpTest Code ICA Calcium, ionized
Laboratory Code
LAB54
Specimen Requirements
Submit only one of the following:
Preferred
Specimen Type: Whole Blood
Container/Tube: Heparinised Syringe
Volume: 3.0 mL
Minimum Volume: 1.0 mL
Collection Instructions: Collect sample in heparinized syringe and mix well to prevent clotting.
Send sample on ice to laboratory immediately.
Acceptable
Specimen Type: Whole Blood
Container/Tube: Green Top (Li Heparin)
Volume: 4.5 mL
Minimum Volume: 0.5 mL
Collection Instructions: Send in primary tube, do not aliquot. Send sample on ice to laboratory immediately.
For patients on Irenat (sodium perchlorate) treatment, collect specimen before administration or after 96 hrs of last dose.
Specimen Stability
| Specimen Type | Whole Blood |
|---|---|
| Ambient | Reject |
| Refrigerate | 4 hours (blood tube to remain sealed) |
| Frozen | Reject |
Methodology
Potentiometry
Days and Times Performed
24 hrs, TAT 1 day
Specimen Condition
| Haemolysis | Not applicable |
|---|---|
| Icterus | Not applicable |
| Lipaemia | Not applicable |
| Others: Aliquoted sample, sample not sent in ice | Reject |
Reference Interval
1.15 – 1.30 mmol/L
Note:
iCA may be falsely low in patients on Irenat (sodium perchlorate) treatment.
Testing Laboratory
National University Hospital
Clinical Chemistry, 67724346
Useful For
The physiologically active form of calcium and a better indicator than total calcium for evaluating calcium metabolism.
Service Code
31022
LOINC Code Information
47596-2
Alias
CA Ionized
Update
Last updated 13/03/2025