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Specimen Collection Manual and Test Catalog

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CALCIUM, IONIZED

Geisinger Epic Procedure Code:  LAB1924    Geisinger Epic ID:  14322

SPECIMEN COLLECTION
Specimen type: 

Serum


Preferred collection container: 
Specimen required: 

Capped, spun 3.5 mL gold-top serum separator tube; minimum 1 mL.



SPECIMEN PROCESSING
Processing instructions: 

Allow to clot. Centrifuge to separate serum within 3 hours of collection. Do not uncap or aliquot.


Transport temperature: 

Refrigerated.


Specimen stability: 

Unopened, centrifuged SST tube stable 3 days refrigerated. Unspun and unopened SST tube stable 3 hours at room temperature or refrigerated.


Rejection criteria: 

Stability limits exceeded. Specimens that have been opened.



TEST DETAILS
Reference interval: 

0-17 years: 1.22-1.37 mmol/L. 18 years and older: 1.13-1.32 mmol/L


Critical values/courtesy alerts: 
Below 0.76 mmol/L; above 1.59 mmol/L.
CPT code(s):  82330
Note: The billing party has sole responsibility for CPT coding.  Any questions regarding coding should be directed to the payer being billed.
The CPT codes provided by GML are based on AMA guidelines and are for informational purposes only.

Test includes: 

Ionized calcium.


Methodology: 
Potentiometric
Synonyms: 

Free calcium, CAI, Ionized calcium, Unbound calcium


Clinical significance: 

Ionized calcium represents the true "bioavailable" calcium in the circulation. It is measured with an ion-selective electrode (ISE) and corrected to a pH of 7.0. Ionized calcium is frequently measured with parathyroid hormone (PTH) to assess hyperparathyroidism.


Doctoral Director(s): 
Hoi-Ying Elsie Yu, PhD, DABCC, FADLM
Sheng-Ying (Margaret) Lo, PhD, DABCC
Benjamin Andress, PhD, DABCC
Review Date:  12/26/2024

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